CN111037765B - Titanium single crystal with target crystal surface and preparation method thereof - Google Patents

Titanium single crystal with target crystal surface and preparation method thereof Download PDF

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CN111037765B
CN111037765B CN201911188369.9A CN201911188369A CN111037765B CN 111037765 B CN111037765 B CN 111037765B CN 201911188369 A CN201911188369 A CN 201911188369A CN 111037765 B CN111037765 B CN 111037765B
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single crystal
axis
sample
rotating
titanium
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CN111037765A (en
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马丽然
石志峰
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Tsinghua University
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Tsinghua University
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28D—WORKING STONE OR STONE-LIKE MATERIALS
    • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
    • B28D5/04—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by tools other than rotary type, e.g. reciprocating tools
    • B28D5/045—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by tools other than rotary type, e.g. reciprocating tools by cutting with wires or closed-loop blades
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28D—WORKING STONE OR STONE-LIKE MATERIALS
    • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
    • B28D5/0058—Accessories specially adapted for use with machines for fine working of gems, jewels, crystals, e.g. of semiconductor material
    • B28D5/0082—Accessories specially adapted for use with machines for fine working of gems, jewels, crystals, e.g. of semiconductor material for supporting, holding, feeding, conveying or discharging work
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/02—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working in inert or controlled atmosphere or vacuum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/16—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of other metals or alloys based thereon
    • C22F1/18—High-melting or refractory metals or alloys based thereon
    • C22F1/183—High-melting or refractory metals or alloys based thereon of titanium or alloys based thereon
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/02—Elements

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)

Abstract

The invention discloses a method for preparing a titanium single crystal with a target crystal surface, which adopts a rotary conversion clamping device and comprises the following steps: providing a titanium single crystal sample having grains with a grain size greater than 5 mm; marking a titanium single crystal sample, and establishing a sample coordinate system of the titanium single crystal sample, wherein the sample coordinate system is defined as Omnl; establishing a crystal coordinate system of a target crystal face in a titanium single crystal sample to obtain Euler angles (alpha, beta, 0) of the target crystal face in the sample coordinate system; clamping a titanium single crystal sample on a rotary conversion clamping device; rotating the first rotating element and the second rotating element according to marks made on the titanium single crystal sample to enable a sample coordinate system Omnl to be coincident with a coordinate system OXYZ of the rotary conversion clamping device so as to zero and fix the coordinate system OXYZ; the second rotating element drives the clamping element to rotate by an angle alpha along a second axis; the first rotating element drives the second rotating element and the clamping element to rotate by an angle beta along a first axis; and cutting the titanium single crystal sample by the cutting element in a cutting direction parallel to the XY plane.

Description

Titanium single crystal with target crystal surface and preparation method thereof
Technical Field
The invention relates to the technical field of crystals, in particular to a titanium single crystal with a target crystal surface and a preparation method thereof.
Background
Titanium has the characteristics of excellent specific strength, fracture toughness, heat resistance, corrosion resistance, biocompatibility and the like, and has wide application in the fields of aerospace, biomedicine, marine chemical industry, automobile nuclear power and the like. The single crystal alpha titanium has a close-packed hexagonal structure, the surface properties (including physical, chemical, mechanical and biological properties) of the single crystal alpha titanium often show remarkable anisotropy, and the single crystal alpha titanium has important influence on the system stability and service life of titanium metal and devices. Therefore, it is necessary to design and prepare a titanium single crystal wafer having a surface with a specific crystallographic orientation according to the application field and the specific requirements.
At present, titanium single crystal wafers are mainly prepared by a method of melting combined with mechanical cutting. The smelting comprises a Czochralski method, a Bridgman method, a suspension region smelting method and the like, and can directly prepare the titanium single crystal with the surface of a low-index crystal face and obtain a titanium single crystal wafer through mechanical cutting. However, this method has two disadvantages, one is that only titanium single crystal with low index crystal face on the surface can be prepared, the required target crystal face can not be obtained, and the price is very high.
Disclosure of Invention
Therefore, it is necessary to provide a method for producing a titanium single crystal having a target crystal surface and a titanium single crystal having a target crystal surface, in order to solve the problem that a titanium single crystal having a desired target crystal surface cannot be obtained by the conventional process.
A method for preparing a titanium single crystal having a target crystal plane surface, using a rotating transforming clamping device, comprising:
providing a titanium single crystal sample having grains with a grain size greater than 5 mm;
marking a titanium single crystal sample, and establishing a sample coordinate system of the titanium single crystal sample, wherein the sample coordinate system is defined as Omnl;
establishing a crystal coordinate system of a target crystal face in the titanium single crystal sample on the sample coordinate system according to the right hand rule to obtain Euler angles (alpha, beta, 0) of the target crystal face in the sample coordinate system;
clamping the titanium single crystal sample on a rotary conversion clamping device, wherein the rotary conversion clamping device comprises a first rotating element, a second rotating element and a clamping element, the second rotating element is arranged on the first rotating element, the clamping element is arranged on the second rotating element, the clamping element comprises a clamping part for clamping the titanium single crystal sample, the first rotating element can drive the second rotating element and the clamping element to rotate by a first axis, the second rotating element can drive the clamping element to rotate by a second axis, and the first axis is perpendicular to the second axis;
rotating the first rotating element and the second rotating element so that the sample coordinate system Omnl coincides with a coordinate system OXYZ of the rotary conversion clamping device according to a mark made on the titanium single crystal sample so as to zero-set the coordinate system OXYZ and fix, wherein in the zero-set coordinate system OXYZ, a Z axis is parallel to the second axis and an X axis is parallel to the first axis;
according to the reverse direction of the right-hand rule, the second rotating element drives the clamping element to rotate by an angle alpha along a second axis and locks the second rotating element;
according to the reverse direction of the right-hand rule, the first rotating element drives the second rotating element and the clamping element to rotate by a beta angle along a first axis and locks the first rotating element; and
and cutting the titanium single crystal sample by the cutting element in a cutting direction parallel to the XY plane.
In one embodiment, the step of providing a sample of titanium single crystal having grains with a grain size greater than 5mm comprises:
carrying out heat treatment on the pure titanium substrate for 24-48 h in a vacuum environment at 1200-1300 ℃; and
cooling the pure titanium base material after the heat treatment, wherein the temperature is reduced in (T)α/β-X，Tα/β+ X), the speed of said cooling is not more than 0.1 deg.C/min, Tα/βThe alpha/beta phase transition temperature of the pure titanium substrate is more than or equal to X and more than or equal to 10 ℃ at the temperature of 100 ℃.
In one embodiment, at greater than Tα/β+ X andor less than Tα/βThe step of cooling down at a temperature of-X.is furnace cooling.
In one embodiment, the pure titanium substrate is cylindrical.
In one embodiment, the step of establishing a crystal coordinate system of a target crystal plane in the titanium single crystal sample and obtaining the euler angle (α, β,0) of the target crystal plane in the sample coordinate system is performed by an electron back scattering diffraction instrument.
In one embodiment, the titanium single crystal sample is a column, the titanium single crystal sample is marked, and the step of establishing a sample coordinate system Omnl of the titanium single crystal sample comprises the following steps:
marking the axis of the cylinder as an axis I; and
the surface perpendicular to the l axis is taken as an mn-face, the m axis and the n axis are perpendicular to each other, and the directions of the m axis and the n axis are marked on the titanium single crystal sample.
In one embodiment, a crystal coordinate system of the target crystal plane is defined as Oxyz, an x-axis is an intersection line of the target crystal plane and the mn-plane, a z-axis is a normal direction of the target crystal plane, an α angle in the euler angles is an included angle between the m-axis and the x-axis, and a β angle is an included angle between the z-axis and the l-axis.
In one embodiment, the first axis is a vertical direction and the second axis is a horizontal direction.
In one embodiment, the rotary conversion clamping device comprises a connecting block, the bottom of the connecting block is fixedly connected with the first rotating element, and the side surface of the connecting block is fixedly connected with the second rotating element.
In one embodiment, the bottom of the connecting block is fixedly connected with the first rotating table, and the side surface of the connecting block is fixedly connected with the second base.
In one embodiment, the clamping element comprises an upper pressing plate, a lower pressing plate and a fastening bolt, the fastening bolt penetrates through the upper pressing plate and the lower pressing plate along the superposition direction of the upper pressing plate and the lower pressing plate and fixes the distance between the upper pressing plate and the lower pressing plate, the clamping part is formed between the upper pressing plate and the lower pressing plate, and the superposition direction is parallel to the first axis.
In one embodiment, the cutting element is provided independently of the rotary transformer, and the cutting element is provided on a side of the clamping element remote from the second rotary element.
In one embodiment, the cutting element is a metal cutting wire.
The titanium single crystal with the target crystal surface is prepared by the preparation method of the titanium single crystal with the target crystal surface.
The preparation method of the titanium single crystal with the target crystal surface can be matched with a rotary conversion clamping device to realize the cutting of the target crystal surface of any orientation in the titanium single crystal sample. The rotary conversion clamping device can rotate the clamping element in two mutually perpendicular directions, and the angle of the clamping element can be accurately positioned by adjusting the angles of the first rotating element and the second rotating element, so that the angle of the titanium single crystal sample clamped by the clamping element can be accurately adjusted. And marking the titanium single crystal sample to determine a sample coordinate system of the titanium single crystal sample and a crystal coordinate system of the target crystal face, so as to obtain an Euler angle required for rotating the sample coordinate system to the target crystal face. And then, the rotation transformation clamping device is reset to zero and fixed by superposing the sample coordinate system and the rotation transformation clamping device coordinate system to form a rotation reference. And then, the first rotating element and the second rotating element are rotated reversely according to the Euler angle, so that the target crystal face can be rotated until the cutting direction of the cutting element is parallel, and the target crystal face with any orientation can be accurately cut.
Further, the method for preparing the titanium single crystal having the target crystal surface according to the embodiment of the present invention only needs to determine the sample coordinate system and euler angle of the titanium single crystal in advance, and can realize accurate control of the angle without performing under an electron microscope during cutting, so that the method for cutting based on the rotational transformation clamping device according to the embodiment of the present invention does not need to consider the operation space for cutting, and is not only suitable for preparing a small sample having the target crystal surface, but also suitable for cutting a large sample, and has a wider application range and higher preparation efficiency.
Drawings
FIG. 1 is a schematic flow chart of a method for producing a titanium single crystal having a target crystal plane surface according to an embodiment of the present invention;
FIG. 2 is a schematic view of a rotary transforming clamping device according to an embodiment of the present invention;
FIG. 3 is a polar view of a target crystal plane in accordance with one embodiment of the present invention;
FIG. 4 is a sample coordinate system diagram and a crystal coordinate system diagram of a titanium single crystal according to an embodiment of the present invention.
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
The embodiment of the invention provides a preparation method of a titanium single crystal with a target crystal surface, which adopts a rotary conversion clamping device and comprises the following steps:
s100, providing a titanium single crystal sample with grain size larger than 5 mm;
s200, marking a titanium single crystal sample, and establishing a sample coordinate system of the titanium single crystal sample, wherein the sample coordinate system is defined as Omnl;
s300, establishing a crystal coordinate system of a target crystal face in the titanium single crystal sample on the sample coordinate system according to a right-hand rule to obtain Euler angles (alpha, beta, 0) of the target crystal face in the sample coordinate system;
s400, clamping the titanium single crystal sample on a rotary conversion clamping device, wherein the rotary conversion clamping device comprises a first rotating element, a second rotating element and a clamping element, the second rotating element is arranged on the first rotating element, the clamping element is arranged on the second rotating element, the clamping element comprises a clamping part for clamping the titanium single crystal sample, the first rotating element can drive the second rotating element and the clamping element to rotate by a first axis, the second rotating element can drive the clamping element to rotate by a second axis, and the first axis is perpendicular to the second axis;
s500, according to marks made on the titanium single crystal sample, rotating the first rotating element and the second rotating element to enable the sample coordinate system Omnl to coincide with a coordinate system OXYZ of the rotary conversion clamping device so as to zero and fix the coordinate system OXYZ, wherein in the zero-set coordinate system OXYZ, a Z axis is parallel to the second axis, and an X axis is parallel to the first axis;
s600, according to the opposite direction of the right-hand rule, the second rotating element drives the clamping element to rotate by an angle alpha along a second axis and locks the second rotating element;
s700, according to the opposite direction of the right-hand rule, the first rotating element drives the second rotating element and the clamping element to rotate by a beta angle along a first axis and lock the first rotating element; and
and S800, cutting the titanium single crystal sample by the cutting element in a cutting direction parallel to the XY plane.
The preparation method of the titanium single crystal with the target crystal surface can be matched with a rotary conversion clamping device to realize the cutting of the target crystal surface of any orientation in the titanium single crystal sample. The rotary conversion clamping device can rotate the clamping element in two mutually perpendicular directions, and the angle of the clamping element can be accurately positioned by adjusting the angles of the first rotating element and the second rotating element, so that the angle of the titanium single crystal sample clamped by the clamping element can be accurately adjusted. And marking the titanium single crystal sample to determine a sample coordinate system of the titanium single crystal sample and a crystal coordinate system of the target crystal face, so as to obtain an Euler angle required for rotating the sample coordinate system to the target crystal face. And then, the rotation transformation clamping device is reset to zero and fixed by superposing the sample coordinate system and the rotation transformation clamping device coordinate system to form a rotation reference. And then, the first rotating element and the second rotating element are rotated reversely according to the Euler angle, so that the target crystal face can be rotated until the cutting direction of the cutting element is parallel, and the target crystal face with any orientation can be accurately cut.
Further, the method for preparing the titanium single crystal having the target crystal surface according to the embodiment of the present invention only needs to determine the sample coordinate system and euler angle of the titanium single crystal in advance, and can realize accurate control of the angle without performing under an electron microscope during cutting, so that the method for cutting based on the rotational transformation clamping device according to the embodiment of the present invention does not need to consider the operation space for cutting, and is not only suitable for preparing a small sample having the target crystal surface, but also suitable for cutting a large sample, and has a wider application range and higher preparation efficiency.
The structure of the rotary conversion clamping device according to the embodiment of the present invention will be further described below.
In one embodiment, the first axis of the rotating conversion clamping device is vertical, and the second axis is horizontal. Of course, the directions of the first axis and the second axis may also be other directions perpendicular to each other, so as to ensure that the planes in which the first rotating element and the second rotating element drive to rotate are perpendicular to each other. The first axis is vertical direction, and the second axis is horizontal direction and is convenient for use first axis and second axis as the reference with the three-dimensional coordinate axis of rotation transformation clamping device coordinate system for the position of rotation transformation clamping device coordinate system is more correct, is more convenient for observe and carries out angle adjustment. The "vertical direction" in this embodiment means the direction of gravitational force, and the "horizontal direction" is a direction perpendicular to the vertical direction.
In an embodiment, the first rotating element rotates around a first rotating axis, the second rotating element rotates around a second rotating axis, the first rotating axis is perpendicular to the second rotating axis, the first rotating element can drive the second rotating element and the clamping element to rotate around the first rotating axis, and the second rotating element can drive the clamping element to rotate around the second rotating axis. The first rotation shaft is a rotation driving shaft of the first rotation member, and the second rotation shaft is a rotation driving shaft of the second rotation member. That is, the first rotating shaft is a first axis, and the shaft rotated by the first rotating element is also a shaft rotated by the first rotating element to drive the second rotating element and the clamping element to rotate. The second rotating shaft is a second axis, and the shaft rotated by the second rotating element is also a shaft driven by the second rotating element to rotate by the clamping element.
In one embodiment, the rotational translation clamping device includes a connecting block for connecting the first rotational member and the second rotational member. In one embodiment, the bottom of the connecting block is fixedly connected with the first rotating element, and the side surface of the connecting block is fixedly connected with the second rotating element. In an embodiment, the first rotating element can rotate by taking a first rotating shaft in the vertical direction as an axis, and the fixed connecting block, the second rotating element connected with the connecting block, and the clamping element are driven to rotate in the same rotating direction as the first rotating shaft. The second rotating element can rotate by taking a second rotating shaft with the second rotating shaft as a horizontal direction as an axis, and drives the clamping element to rotate in the same direction as the second rotating shaft. In one embodiment, the first rotating element and the second rotating element can be respectively connected with the connecting block through bolts.
In one embodiment, the first rotating member includes a first base, a first rotating table, and the first rotating shaft connecting the first base and the first rotating table, and the first rotating table is driven to rotate when the first rotating shaft rotates. In an embodiment, the second rotating element includes a second base, a second rotating platform, and a second rotating shaft connecting the second base and the second rotating platform, and the second rotating shaft drives the second rotating platform to rotate when rotating. In an embodiment, the first rotating shaft and/or the second rotating shaft may be connected to a motor to drive the first rotating shaft and/or the second rotating shaft to rotate. In one embodiment, the first base and the first rotating table are perpendicular to the first rotating shaft, and the second base and the second rotating table are perpendicular to the second rotating shaft. In an embodiment, the bottom of the connecting block is fixedly connected with the first rotating table, and the side surface of the connecting block is fixedly connected with the second base. In one embodiment, the connecting block may have a right-angle structure, a right-angle bottom surface of the right-angle structure may be connected to the first rotating table, and a right-angle side surface adjacent to the right-angle bottom surface may be connected to the second base. Preferably, the right-angle bottom surface and the right-angle side surface can be planes, and the first rotating table and the second base can be planes, so that the connecting block can be conveniently fixed with the first rotating element and the second rotating element. The connecting block plays a connecting role on one hand and a supporting role on the other hand.
In one embodiment, the clamping member is fixedly disposed on the second rotating member.
In one embodiment, the clamping element comprises an upper pressing plate, a lower pressing plate and a fastening bolt, the fastening bolt penetrates through the upper pressing plate and the lower pressing plate along the superposition direction of the upper pressing plate and the lower pressing plate and fixes the distance between the upper pressing plate and the lower pressing plate, and a clamping part is formed between the upper pressing plate and the lower pressing plate. The stacking direction is parallel to the first axis, and the stacking direction can also be parallel to the first rotating shaft and perpendicular to the second rotating shaft.
In an embodiment, the clamping portion may be used for clamping a cylindrical device, a radial direction of the cylindrical device may be a stacking direction of the upper pressing plate and the lower pressing plate, and the upper pressing plate and the lower pressing plate may fix the cylindrical device by clamping at opposite sidewalls of the cylindrical device. The length direction of the cylindrical device may be parallel to or coincident with the second axis or second axis of rotation. The cylindrical device may extend in a length direction beyond the clamping portion, and the extended portion may be cut to form a specific shape or to obtain a target crystal plane of a predetermined orientation.
In one embodiment, the clamping member may include a counter balance pad that may be disposed between the upper platen and the lower platen to support a gap between the upper platen and the lower platen.
In one embodiment, the rotation conversion clamping device includes a fixing block, and the fixing block is disposed at a bottom end of the rotation conversion clamping device, and may be disposed at a bottom of the first rotating element, for example, disposed in connection with a bottom surface of the first base. The fixed block is arranged at the bottom end of the rotary conversion clamping device and is used for fixing the rotary conversion clamping device on other devices, such as a workbench of a cutting device. The fixing block may include a connection part for connection with the first rotating member and a support part for supporting the rotation transformation holding device, and the connection part and the support part may be perpendicular to each other.
The embodiment of the invention also provides a rotary conversion cutting system which comprises a cutting element and the rotary conversion clamping device of any one of the embodiments, wherein the cutting element can cut a device clamped by the clamping part.
In one embodiment, the cutting element is disposed independently of the rotary transformation device. In another embodiment, the rotary transformation device may be connected to a device having a cutting element. In an embodiment, the cutting element is provided on a side of the clamping element remote from the second rotating element.
In one embodiment, the cutting element is a metal cutting line, the surface area of the cutting line is small, accurate cutting can be achieved, and the smoothness of the cutting surface is improved.
The method for producing a titanium single crystal having a target crystal plane surface according to the embodiment of the present invention will be further described below.
In step S100, the step of providing the titanium single crystal sample having the grain size of more than 5mm may be to heat treat the pure titanium substrate in the β phase region for a long time, and then anneal the pure titanium substrate by using the step-controlled cooling. The inventor finds that compared with the traditional single crystal preparation methods such as long-time annealing in an alpha phase region or short-time (2 hours) annealing in a beta phase region, the titanium single crystal prepared by the method of long-time heat treatment in the beta phase region and segmented speed-controlled cooling in the embodiment of the application has larger crystal grains, and the titanium single crystal sample with larger crystal grains is more suitable for being cut by the method in the embodiment of the application to obtain the surface of the target crystal face.
In an embodiment, step S100 may include:
s120, carrying out heat treatment on the pure titanium substrate for 24-48 h in a vacuum environment at 1200-1300 ℃; and
s140, cooling the pure titanium base material subjected to the heat treatment, wherein the temperature is in the range of (T)α/β-X， Tα/β+ X), the speed of said cooling is not more than 0.1 deg.C/min, Tα/βThe alpha/beta phase transition temperature of the pure titanium substrate is more than or equal to X and more than or equal to 10 ℃ at the temperature of 100 ℃.
Tα/βThe alpha/beta phase transition temperature of the pure titanium substrate is higher than Tα/βWhen the pure titanium substrate is beta-phase, the beta-phase is lower than Tα/βWhen the pure titanium substrate is an alpha phase. The pure titanium substrate of the embodiment of the invention refers to a sample with the total mass content of impurities less than 0.1%, that is, the influence of the impurities on the crystal structure of the pure titanium substrate is negligible.Tα/βGenerally about 882 ℃. This embodiment is achieved by applying (T)α/β-X，Tα/β+ X) temperature range to avoid disordered transformation of the pure titanium substrate in the beta and alpha phases, so that alpha phase titanium single crystals with larger grains can be obtained by the method of this example. The grain size of the titanium single crystal prepared by this example may be 5mm to 20 mm.
In one embodiment, greater than Tα/β+ X andor less than Tα/βThe step of cooling down at the temperature of-X, can be furnace cooling, thereby accelerating the efficiency of titanium single crystal production.
In one embodiment, the heat treatment in the vacuum environment may be performed in a vacuum heat treatment furnace, or may be performed in a non-vacuum heat treatment furnace by vacuum packaging the pure titanium substrate with a high temperature resistant material such as quartz glass.
In one embodiment, the pure titanium substrate may be of any shape, preferably cylindrical, such as a titanium rod. The cylindrical structure facilitates defining a sample coordinate system and aligning the sample coordinate system with the coincidence of the rotating transforming fixture.
In an embodiment, before the pure titanium substrate is subjected to the heat treatment, a step of removing impurities on the surface of the pure titanium substrate is further included, and specifically, the step of cleaning the pure titanium substrate with an organic solvent to remove oil stains on the surface may be further included. The organic solvent can be selected from acetone, ethanol, etc.
In step S200, a mark is marked on the titanium single crystal sample, and a sample coordinate system of the titanium single crystal sample is established according to the mark. Meanwhile, marking the sample facilitates accurate determination of the axes of the sample coordinate system after the titanium single crystal sample is clamped on the clamping member in step S500. The marking on the titanium single crystal sample can be carried out on a certain surface of the sample. In one embodiment, the titanium single crystal sample may be cylindrical to facilitate subsequent repeated cutting along the length of the cylinder. Preferably regular cylindrical in shape, to facilitate subsequent gripping and rotation. In one embodiment, the titanium single crystal sample may be cylindrical, and the side of the cylindrical titanium single crystal sample may be cut into a facet parallel to the axis to orient the titanium single crystal sample. In another embodiment, to facilitate establishing the crystal coordinate system, the titanium single crystal sample may be processed into a rectangular prism or a square prism, three mutually perpendicular sides are respectively used as three perpendicular axes of the sample coordinate system, and the three mutually perpendicular sides are marked to record names of the axes corresponding to the sides.
In one embodiment, the titanium single crystal sample is a column, the titanium single crystal sample is marked, and the step of establishing the sample coordinate system of the titanium single crystal sample comprises the following steps:
marking the axis of the cylinder as an axis I; and marking the surface vertical to the l axis as an mn surface, wherein the m axis and the n axis are vertical to each other, and marking the directions of the m axis and the n axis on the titanium single crystal sample.
In step S300, a crystal coordinate system of a target crystal plane in the titanium single crystal sample is established, and the step of obtaining the euler angle (α, β,0) of the target crystal plane in the sample coordinate system is performed by an electron back scattering diffraction instrument. And observing the crystal fine structure of the titanium single crystal sample by an electron back scattering diffraction instrument to find a target crystal face, and obtaining a crystal coordinate system of the target crystal face. The euler angle is the rotation angle of the sample coordinate system to the crystal coordinate system.
In an embodiment, a crystal coordinate system of the target crystal plane is defined as Oxyz, an x-axis is an intersection line of the target crystal plane and the mn-plane, a z-axis is a normal direction of the target crystal plane, an α angle in the euler angles is an included angle between the m-axis and the x-axis, and a β angle is an included angle between the z-axis and the l-axis.
In step S400, when the titanium single crystal sample is a pillar shape, the length direction of the pillar shape may be parallel to the second axis or the second rotation axis, or may coincide with an extension of the second axis or an extension of the second rotation axis.
In step S500, the sample coordinate system Omnl coincides with the coordinate system xyz of the rotation conversion holding means, that is, the l-axis, m-axis, and n-axis of the titanium single crystal sample are parallel to and coincide with the Z-axis, X-axis, and Y-axis of the rotation conversion holding means, respectively. The sample coordinate system of the titanium single crystal sample is determined according to the marks, and the coordinate system OXYZ of the rotary conversion clamping device can be coincided with the sample coordinate system Omnl only by adjusting the first rotating element and the second rotating element. In one embodiment, the titanium single crystal sample is a cylinder, and the axis is the axial direction of the cylinder. In the zeroing coordinate system oyxyz, the Z-axis is defined as the direction parallel to the second axis and the X-axis is parallel to the first axis. That is, in the zero-set rotation transformation clamping device, the second axis is parallel to the axis of the titanium single crystal sample, and the first axis is parallel to the m-axis marked on the titanium single crystal sample. Note that even if the first rotating element and the second rotating element rotate by the angle after zeroing, the coordinate system xyz of the rotation conversion holding device remains unchanged, and thus can be used as a reference for rotation to the euler angle.
In steps S600 and S700, rotating the second axis, i.e., rotating the second rotation axis, drives the titanium single crystal sample clamped by the clamping element to rotate by an angle α. Rotating the first axis, namely rotating the first rotating shaft, drives the titanium single crystal sample clamped by the clamping element to rotate by an angle beta. The first rotating element and the second rotating element are rotated to drive the titanium single crystal sample, so that a target crystal plane of the titanium single crystal sample is parallel to an XY plane of a coordinate system of the rotating clamping device.
In step S800, a cutting surface formed by cutting the titanium single crystal sample by the cutting element in a direction parallel to the XY plane is the target crystal plane.
In one embodiment, the method further comprises a step of reducing the surface roughness of the titanium single crystal with the target crystal plane surface after step S800. In an embodiment, the step of reducing the surface roughness may be a chemical mechanical polishing method, which may be a conventional method of reducing the surface roughness and will not be described in detail. Preferably, the method further comprises the step of removing the polishing solution after the chemical mechanical polishing.
The embodiment of the invention also provides the titanium single crystal with the target crystal surface prepared by the preparation method of the titanium single crystal with the target crystal surface.
Examples
Referring to fig. 2, the rotary transforming clamping device includes a right-angle fixing block 500, a first rotating member 100, a right-angle connecting block 400, a second rotating member 200 and a clamping member 300, which are connected in sequence. The coordinate system of the rotation transformation clamping device is defined as OXYZ.
The right-angle fixing block 500 is a base of the rotation transformation clamping device and is used for being connected with a workbench of a wire cutting machine with a metal cutting wire, and the bottom surface of the right-angle fixing block 500 is an XY plane of the rotation transformation clamping device.
The first rotating member 100 includes a first base 140, a first rotating table 120, and a first rotating shaft (not shown) perpendicular to and disposed between the first base 140 and the first rotating table 120. The second rotating member 200 includes a second base 240, a second rotating stage 220, and a second rotating shaft (not shown) perpendicular to and disposed between the second base 240 and the second rotating stage 220. The first base 140 is connected to the right-angle fixing block 500 by bolts, and the rotation axis of the first rotating stage 120 is the X axis of the rotational transformation clamping device, and the first rotating stage 120 can realize the rotational transformation of the angle β of Euler angles (α, β, 0). The bottom end of the right-angle connecting block 400 is fixed to the first rotating platform 120 by bolts, and the side surface is connected to the second base 240 by bolts.
The clamping member 300 comprises a lower pressing plate 320, an upper pressing plate 310, and a fastening bolt 330 and a balance cushion block 340 penetrating through the stacking direction of the lower pressing plate 320 and the upper pressing plate 310, wherein a clamping part is formed between the lower pressing plate 320 and the upper pressing plate 310 and is used for clamping the titanium single crystal sample 600. The second rotating stage 220 is connected to the lower pressing plate 320 of the clamping member 300, and can realize the rotation transformation of the angle alpha in the Euler angles (alpha, beta, 0). Before the rotation conversion, the rotation axis of the second rotating member 200 is ensured to be parallel to the Z-axis of the rotation conversion holding device.
A method for producing a titanium single crystal having a target crystal plane surface by using the above-described rotary shifting jig will be described.
The specific process comprises the following steps:
s100, selecting a high-purity titanium rod with the purity of 99.999 percent and the diameter of 13mm as a pure titanium base material, and ultrasonically cleaning the pure titanium base material by using acetone, alcohol and deionized water in sequence to remove oil stains on the surface. The titanium single crystal sample 600 with 10 mm-grade super large crystal grains is prepared by adopting the beta phase region long-time vacuum annealing heat treatment with sectional speed control cooling, which comprises the following specific steps:
and (3) carrying out vacuum packaging on the high-purity titanium rod by adopting a quartz glass tube, and placing the high-purity titanium rod in a heat treatment furnace for vacuum annealing heat treatment. The heat treatment temperature was 1200 ℃ and the heat treatment time was 24 hours. Cooling to 920 ℃ along with the furnace after heat treatment, cooling to 860 ℃ at the speed of 0.1 ℃/min, and cooling to room temperature along with the furnace. The quartz glass tube was broken to obtain a cylindrical titanium single crystal sample 600 having crystal grains of about 10mm in diameter.
S200, setting a sample coordinate system Omnl: the titanium single crystal sample 600 of this embodiment is cylindrical in shape, and for the convenience of holding and positioning, a facet parallel to the axis of the cylinder is machined on the side of the cylinder. The normal to the facets is taken as the m-axis, the axis of the cylinder is taken as the l-axis, and Omnl is taken as the sample coordinate system according to the right hand rule.
S300, determining the crystallographic coordinate system Oxyz of the target crystal plane (hkl) and its Euler angle (α, β,0) in the sample coordinate system Omnl: and selecting the mn surface of the sample, cutting a slice with the thickness of 2mm along the mn surface, and grinding and polishing the slice. The wafer was subjected to Electron Back Scattering Diffraction (EBSD) to determine the crystallographic orientation of the target crystal plane (ensuring that the sample coordinate system Omnl of the wafer crystal coincides with the sample stage coordinate system Om 'n' l 'of the EBSD) and to obtain a polar diagram (as shown in fig. 2) of the target crystal plane, where B' is the polar emittance plane (mn plane) projection point of the target crystal plane (hkl). Referring to fig. 3, on a reference sphere, a pole B of the target facet (hkl) on the sphere can be obtained. A straight line AA' perpendicular to OB is drawn on the red plane, OA is used as an x axis, OB is used as a z axis, and a crystallographic coordinate system Oxyz where the target crystal plane (hkl) is located is constructed according to the right-hand rule. Meanwhile, according to the Euler angle rotation transformation rule, the sample coordinate system Omnl is transformed to the crystallographic coordinate system Oxyz in which the target crystal plane (hkl) is located, so as to obtain the Euler angle (α, β,0), wherein α ═ mOA and β ═ BOl.
S400, S500, clamping the titanium single crystal sample 600 and zeroing the rotary conversion clamping device: the titanium single crystal sample 600 was fixed to the clamping portion, and the first rotating element 100 and the second rotating element 200 were zeroed to ensure that the sample coordinate system Omnl of the titanium single crystal sample 600 coincides with the coordinate system xyz of the rotary conversion clamping device, while ensuring that the second rotation axis was parallel to the Z-axis of the rotary conversion clamping device. After zeroing, the axis of the cylindrical titanium single crystal sample 600 is parallel to the second rotation axis, and the normal of the facet is parallel to the first rotation axis.
S600, S700, Euler rotation transformation: firstly, taking the Z axis as a rotating shaft, rotating the second rotating element 200 by an angle alpha and locking the second rotating element according to the opposite direction of a right-hand rule; then, the first rotating member 100 is rotated by an angle β and locked in the opposite direction of the right-hand rule with the X-axis as the rotation axis. After two times of rotation transformation, the target crystal face (hkl) is parallel to the XY plane of the rotation transformation clamping device.
S800, fixing a rotary conversion clamping device: the right angle fixture block 500 of the rotary conversion fixture is fixed to the table of the wire cutting machine and ensures that the XY plane is parallel to the metal cutting wire (cutting element). And cutting the titanium single crystal sample 600 by using a metal cutting wire along a direction parallel to the XY plane, wherein the cutting surface is the target crystal plane (hkl).
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (13)

1. A method for producing a titanium single crystal having a target crystal plane surface, characterized by using a rotary conversion jig and comprising:
providing a titanium single crystal sample having grains with a grain size greater than 5 mm;
marking a titanium single crystal sample, and establishing a sample coordinate system of the titanium single crystal sample, wherein the sample coordinate system is defined as Omnl;
establishing a crystal coordinate system of a target crystal face in the titanium single crystal sample on the sample coordinate system according to the right hand rule to obtain Euler angles (alpha, beta, 0) of the target crystal face in the sample coordinate system;
clamping the titanium single crystal sample on a rotary conversion clamping device, wherein the rotary conversion clamping device comprises a first rotating element, a second rotating element and a clamping element, the second rotating element is arranged on the first rotating element, the clamping element is arranged on the second rotating element, the clamping element comprises a clamping part for clamping the titanium single crystal sample, the first rotating element can drive the second rotating element and the clamping element to rotate by a first axis, the second rotating element can drive the clamping element to rotate by a second axis, and the first axis is perpendicular to the second axis;
rotating the first rotating element and the second rotating element so that the sample coordinate system Omnl coincides with a coordinate system OXYZ of the rotary conversion clamping device according to a mark made on the titanium single crystal sample so as to zero-set the coordinate system OXYZ and fix, wherein in the zero-set coordinate system OXYZ, a Z axis is parallel to the second axis and an X axis is parallel to the first axis;
according to the reverse direction of the right-hand rule, the second rotating element drives the clamping element to rotate by an angle alpha along a second axis and locks the second rotating element;
according to the reverse direction of the right-hand rule, the first rotating element drives the second rotating element and the clamping element to rotate by a beta angle along a first axis and locks the first rotating element; and
and cutting the titanium single crystal sample in a cutting direction parallel to the XY plane by using a cutting element.
2. The method of producing a titanium single crystal having a target crystal plane surface according to claim 1, wherein the step of providing a sample of a titanium single crystal having a grain diameter of more than 5mm comprises:
carrying out heat treatment on the pure titanium substrate for 24-48 h in a vacuum environment at 1200-1300 ℃; and
cooling the pure titanium base material after the heat treatment, wherein the temperature is reduced in (T)α/β-X,Tα/β+ X), the speed of said cooling is not more than 0.1 deg.C/min, Tα/βThe alpha/beta phase transition temperature of the pure titanium substrate is more than or equal to X and more than or equal to 10 ℃ at the temperature of 100 ℃.
3. The method of producing a titanium single crystal having a target crystal plane surface according to claim 2, characterized in that the temperature is set to be higher than Tα/β+ X andor less than Tα/βThe step of desuperheating at a temperature of-X is furnace cooling.
4. The method of producing a titanium single crystal having a target crystal plane surface according to claim 2, wherein the pure titanium base material is a columnar shape.
5. The method for producing a titanium single crystal having a surface of a target crystal plane according to claim 1, wherein the step of establishing a crystal coordinate system of the target crystal plane in the titanium single crystal sample and obtaining the euler angle (α, β,0) of the target crystal plane in the sample coordinate system is performed by an electron back scattering diffractometer.
6. The method for producing a titanium single crystal having a target crystal plane surface according to claim 1, wherein the titanium single crystal sample is a columnar sample, a mark is made on the titanium single crystal sample, and the step of establishing a sample coordinate system Omnl of the titanium single crystal sample comprises:
marking the axis of the cylinder as an axis I; and
the surface perpendicular to the l axis is taken as an mn-face, the m axis and the n axis are perpendicular to each other, and the directions of the m axis and the n axis are marked on the titanium single crystal sample.
7. The method of producing a titanium single crystal having a target crystal plane surface according to claim 6,
the crystal coordinate system of the target crystal face is defined as Oxyz, the x axis is an intersection line of the target crystal face and the mn face, the z axis is a normal direction of the target crystal face, an alpha angle in the Euler angle is an included angle between the m axis and the x axis, and a beta angle is an included angle between the z axis and the l axis.
8. The method of producing a titanium single crystal having a target crystal plane surface according to claim 1, wherein the first axis is a vertical direction and the second axis is a horizontal direction.
9. The method for producing a titanium single crystal having a target crystal plane surface according to claim 1, wherein the rotary conversion holding means comprises a connection block, a bottom of the connection block is fixedly connected to the first rotating member, and a side surface of the connection block is fixedly connected to the second rotating member.
10. The method for producing a titanium single crystal having a target crystal plane surface according to claim 9, wherein the first rotating element includes a first base, a first rotating table, and a first rotating shaft connecting the first base and the first rotating table, and the first rotating table is rotated when the first rotating shaft rotates; the second rotating element comprises a second base, a second rotating platform and a second rotating shaft which is connected with the second base and the second rotating platform, and the second rotating shaft drives the second rotating platform to rotate when rotating; the first base and the first rotating table are respectively vertical to the first rotating shaft, and the second base and the second rotating table are respectively vertical to the second rotating shaft; the bottom of connecting block with first revolving stage fixed connection, the side of connecting block with second base fixed connection.
11. The method for producing a titanium single crystal having a target crystal plane surface according to claim 1, wherein the clamping member includes an upper platen, a lower platen, and a fastening bolt that passes through the upper platen and the lower platen in a direction in which the upper platen and the lower platen are superimposed and fixes a distance between the upper platen and the lower platen, the clamping portion being formed between the upper platen and the lower platen, the direction in which the upper platen and the lower platen are superimposed being parallel to the first axis.
12. The method for producing a titanium single crystal having a target crystal plane surface according to claim 1, wherein the cutting element is provided independently of the rotary conversion clamping device, and the cutting element is provided on a side of the clamping element away from the second rotating element.
13. A titanium single crystal having a target crystal plane surface produced by the method for producing a titanium single crystal having a target crystal plane surface according to any one of claims 1 to 12.
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