CN1279150A

CN1279150A - Method and equipment for forming ceramic parts

Info

Publication number: CN1279150A
Application number: CN 00108469
Authority: CN
Inventors: 黄安基
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-06-08
Filing date: 2000-06-08
Publication date: 2001-01-10
Anticipated expiration: 2020-06-08
Also published as: CN1111470C

Abstract

A technology for shaping ceramic sealing parts includes such steps as proportioning raw materials, grinding, spray granulating to obtain ceramic powder, loading in shaping mould, top pressing to form central hole and step structure, sintering and grinding the end face. Its shaping mould is composed of upper and lower punching heads, internal core, and movable internal and external ejecting rods. Its advantages include simple process, high productivity, and high size precision and compactness of products.

Description

The forming ceramic parts method and apparatus

The present invention relates to a kind of forming method of ceramic component and the forming method and the mould of the special equipment, particularly a kind of ceramic seal gasket of this method of realization.

Ceramic component is because wearability is good, thermal coefficient of expansion is little, cost is low, is widely used in the various device alternative metals or non-metal component.The existing method of making ceramic component, as slip casting method and extrusion, its technical essential is that preparation contains the ceramic size that ceramic powders and other binding agent etc. are formed, after gelling or extrusion modling, reburn and form goods, with the ceramic component that this forming method is made, dimensional accuracy is not high, contain a lot of pores and defect in the goods, density is relatively poor.Therefore, high-quality precise ceramic component, it generally is the process of sintering again after adopting ceramic powders directly dry-pressing formed, as the patent No. is 92104473 (notification numbers 7070361, day for announcing 93.03.31) patent of invention, a kind of forming method and mould thereof of ceramic rod are disclosed, by the metal internal mold, the rubber external mold, sealing shroud or sealing-plug constitute mould, adopt isostatic compaction method processing ceramic roller rod embryo spare, the tubular idle loop that the batching that is about to process places metal internal mold and rubber external mold to constitute, and sealing both ends, insert static pressure such as implementation pressurization in the autoclave then, the release demoulding then.It is little that this method has contraction distortion, linearity is good, and size is accurate, the density advantage of uniform, but adopt the autoclave pressurization, complex process, efficient is low, the cost height, and this forming method only is suitable for making shape and structure simply as ceramic components such as ceramic rod, rollers, for baroque parts as being used for the ceramic seal gasket of plasma separator, because the stepped structure of sealing sheet and centre bore is arranged adopts this method to be difficult to realize industrialization, production in enormous quantities.

The objective of the invention is to design a kind of forming method and mould of producing ceramic seal gasket, have the efficient height, cost is low, advantages of simple operation, the product strength height of production, good compactness.

Ceramic seal gasket in the plasma separator, be that planar friction by its end face seals, therefore the precision of diaphragm seal structure, size, intensity, density etc. all there are higher requirement, the invention provides a kind of forming method and mould of making the sealing sheet.

This forming method comprises the steps: 1. preparation raw materials: take by weighing each component in proportion, the content of component is Al ₂O ₃: MgO: SiO ₂: Y ₂O ₃: SmO=95～96%: 2～3%: 1～2%: 0.01～0.05%: 0.01～0.05%, the polyvinyl alcohol of interpolation 2% is made binding agent.2. the raw material humidification is levigate in ball mill, and spray-dried again machine mist projection granulating is made ceramic powders.3. ceramic powders is placed mould, with 800～1200kg/cm ²Pressure, be pressed into the blank of centre bore after, roof pressure goes out step structure on the substep.4. ceramic form is put

In molybdenum disilicide rod stove, in the neutral gas environment, temperature is 1550-1600 ℃ of sintering 22 hours, makes ceramic.5. with the cross grinding of ceramic, the formation roughness is the plane of Ra≤0.2 μ m.

The mould of above-mentioned press ceramic diaphragm seal comprises upper punch, low punch, inner core, outer push rod and interior push rod, and outer top stem casing is located in the low punch, interior top stem casing is located in the outer push rod, and outer push rod, interior push rod all can be up and down.

This forming method adopts the direct extrusion forming of ceramic powders, and technology is simple, is suitable for production fast in enormous quantities, and the ceramic seal gasket contraction distortion of making is little, the dimensional accuracy height.Utilize the inside and outside push rod of mould to suppress step by step, form step structure, the each several part pressurized is even in the pressing process, can delamination, and the compact structure of goods is good.

Below in conjunction with drawings and Examples the present invention is described in further detail.

Fig. 1. be the ceramic seal gasket that utilizes forming method of the present invention to produce.

Fig. 2. be the forming die structure schematic diagram of making ceramic seal gasket shown in Figure 1.

Process provided by the invention is used for producing the ceramic seal gasket of plasma separating unit, and its structure as shown in Figure 1, it is the disk of a center drilling 1, an end face 2 of disk is stepped, and other end 3 is the plane, and this end face 3 produces sealing effectiveness with the separator friction.

Produce this ceramic seal gasket, take by weighing each component at first in proportion, the ratio of each component is Al ₂O ₃: MgO: SiO ₂: Y ₂O ₃: SmO=95～96%: 2～3%: 1～2%: 0.01～0.05%: 0.01～0.05%, and add 2% polyvinyl alcohol and make the binding agent constitutive material.This raw material is added water soak, in ball mill, mix levigately, send in the spray dryer, form ceramic powders, place mould to pressurize ceramic powders again through the spraying oven dry.

Mould comprises upper punch 4, low punch 5, inner core 8, outer push rod 6 and interior push rod 7 as shown in Figure 2, and outer push rod 6 is sheathed in the low punch 5, interior push rod 7 is sheathed in the outer push rod 6, and outer push rod 6, interior push rod 7 are promoted and can be moved up and down by molding press.Ceramic powders places the die cavity of low punch 5, and upper punch 4 is with 800～1200kg/cm ²Pressure inside and outside push rod is depressed, cooperate by upper punch 4 and inner core 8, ceramic powders is pressed into the ceramic briquet of centre bore 1, roof pressures go out stepped end face 2 on then outer push rod 6, interior push rod 7 substeps, make ceramic body.

Ceramic body is placed in the molybdenum disilicide rod stove, in the neutral gas environment, with 1550～1600 ℃ of temperature sintering 22 hours, the Low fire ceramic goods.With the end face 3 usefulness diamond dust grinding formation roughness of goods is the plane of Ra≤0.2 μ m.

Claims

1, the forming method of ceramic seal gasket comprises the steps:

(1) preparation raw material: take by weighing each component in proportion, the content of component is Al ₂O ₃: MgO: SiO ₂: Y ₂O ₃: SmO=95～96%: 2～3%: 1～2%: 0.01～0.05%: 0.01～0.05%, the polyvinyl alcohol of interpolation 2% is made binding agent;

(2) the raw material humidification is levigate in ball mill, spray-dried again machine mist projection granulating is made ceramic powders;

(3) ceramic powders is placed mould, with 800～1200kg/cm ²Pressure, be pressed into the blank of centre bore after, roof pressure goes out step structure on the substep;

(4) ceramic form is placed in the molybdenum disilicide rod stove, in the neutral gas environment, temperature is 1550-1600 ℃, and sintering was made ceramic in 22 hours;

(5) with the cross grinding of ceramic, the formation roughness is the plane of Ra≤0.2 μ m.

2, the mould that uses in the described forming method of claim 1, it is characterized in that: comprise upper punch, low punch, inner core, outer push rod and interior push rod, outer top stem casing is located in the low punch, interior top stem casing is located in the outer push rod, and outer push rod, interior push rod all can be up and down.