CN103160705A - Lead-free low-temperature alloy for 140-DEG C burned-out cores of fuses and preparation method of lead-free low-temperature alloy - Google Patents

Abstract

The invention relates to a lead-free low-temperature alloy for 140-DEG C burned-out cores of fuses and a preparation method of the lead-free low-temperature alloy. The lead-free low-temperature alloy comprises the following raw materials in percentage by weight: 49%-51% of Bi, 7.5%-8. 5% of In and the balance of Sn. The preparation method comprises the following steps of: placing metallic stannum in a stainless steel crucible, heating on an electric furnace, adding metallic bismuth at 250 DEG C-280 DEG C after melting the stannum, adding metallic indium after melting down, conventionally adding a degassing agent for degassing after melting down, deslagging and casting to obtain a low-temperature alloy bar with needed size. The lead-free low-temperature alloy containing the Sn, Bi and In is used for manufacturing the burned-out cores with the melting point of 140+/-2 DEG C of the thermal fuses; the low-temperature alloy is an eutectic alloy, has the characteristics of uniform components, narrow melting point range, low cost and the like and is a lead-free environment-friendly material; and the low-temperature alloy has very good social benefits and economic benefits.

Description

140 ℃ of fuse burn-out core lead-free low-temperature Alloy And Preparation Methods

Technical field

The invention belongs to the alloy field, relate to the lead-free low-temperature alloy, especially a kind of 140 ℃ of fuse burn-out core lead-free low-temperature Alloy And Preparation Methods.

Background technology

Fusible core is the heart of Thermal Cutoffs, be the technological core of Thermal Cutoffs production technique, traditional Thermal Cutoffs mostly is tinsel, as a kind of material-lead that is harmful to environment, be detrimental to health in production and use procedure, environment is had great pollution.

Low-temperature alloy can be used for the protection of electronic circuit in electron trade, multiplex fusing core in making Thermal Cutoffs.It is that company is lived by thousand of the alpha of the U.S. and Japan that current low-temperature alloy leads the production firm of world's modern technique.

According to the retrieval, find the following patent documentation relevant to the application, wherein CN102296208A discloses a kind of lead-free low-temperature alloy of the fusing core for making Thermal Cutoffs, and its raw material consists of and weight percentage ranges is respectively: Bi:34%-36%; Zn:3.5%-4.5%; Sn: surplus; The step of its preparation method is: metallic tin is put into stainless crucible, heat on electric furnace, after the tin fusing, under 250-280 ℃, add metallic zinc, fusion clear after, then add bismuth metal, air release agent is degassed, slagging-off to carry out conventional adding after melting clearly, is cast into the low-temperature alloy rod that needs size.Patent documentation CN102912204A discloses a kind of lead-free low-temperature Alloy And Preparation Method and application, and this low-temperature alloy is comprised of tin, bismuth, three kinds of metals of indium, and each weight percentages of components is as follows: tin 15-17%; Bismuth 32-34%; Surplus is indium, and its preparation methods steps is: ⑴ melts tin; ⑵ melt bismuth; ⑶ melt indium; ⑷ degassed; ⑸ casting.Patent documentation CN101812623A discloses a kind of novel environment-friendly low-temperature alloy and preparation method thereof, and it mainly is made of indium, tin, bismuth, zinc, silver metal, on the basis that is associated gold at Bi-In-Sn, adds Zn, the metals such as Ag.

Front two pieces in above-mentioned patent documentation is the technical scheme of protection of the applicant application of this patent; from the application's other part be the composition of its alloy and component content different; the fusing point of final alloy is different; belong to different products; the 3rd piece of file is other applicants' technical scheme; have larger difference with the application's technical scheme, its product fusing point and component content are all different.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art part, provide a kind of melting range narrow, cost is low, 140 ℃ of fuse burn-out core lead-free low-temperature alloys of leadless environment-friendly, the preparation method of this simple, easy to operate alloy of step is provided simultaneously, and the fuse burn-out core of this alloy preparation, the fusing point of the low-temperature alloy of present method preparation is 140 ± 2 ℃.

The objective of the invention is to be achieved through the following technical solutions:

A kind of 140 ℃ of fuse burn-out core lead-free low-temperature alloys, its raw material consists of and weight percentage ranges is respectively:

Bi：49%-51%；

In：7.5%-8.5%；

Sn: surplus.

And its raw material consists of and weight percent is:

Bi：50%；

In：8%；

Sn：42%。

A kind of preparation method of 140 ℃ of fuse burn-out core lead-free low-temperature alloys, step is:

⑴ heat metallic tin, treats the tin fusing;

⑵ add bismuth metal under 250-280 ℃, fusion clear after, then add indium metal, moltenly carry out conventional adding after clear air release agent be degassed, slagging-off, be cast into the low-temperature alloy rod that needs size.

A kind of 140 ℃ of fuse burn-out cores, with extrusion machine extruding low-temperature alloy rod, extruding needs the low-temperature alloy of size silk as the fusing core of Thermal Cutoffs.

Advantage of the present invention and positively effect are:

1, the lead-free low-temperature alloy that contains Sn, Bi, In of the present invention's preparation, ratio by the various compositions of meticulous adjusting, make the fusing point of the alloy of preparing reach 140 ± 2 ℃, melting range is narrow, this low-temperature alloy is eutectic alloy, have the characteristics such as homogeneous chemical composition, cost are low, be used for making the fusing core of Thermal Cutoffs, safe and reliable.

2, low-temperature alloy of the present invention is the leadless environment-friendly material, can replace traditional tinsel, and its composition is not leaded, is therefore the leadless environment-friendly material, has good social benefit and economic benefit.

Embodiment

Further illustrate the present invention below in conjunction with specific embodiment; It is emphasized that: to those skilled in the art, can be improved according to the above description or conversion, and all these improve and conversion all should belong to the protection domain of claims of the present invention.

A kind of 140 ℃ of fuse burn-out core lead-free low-temperature alloys, its concrete composition is Sn ₄₂Bi ₅₀In ₈, concrete composition and weight proportion are as follows:

Bi：50%；

In：8%；

Sn：42%。

Can also adopt following formula, its summation is 100.

Chemical composition	Sn	Bi	In
				100%	41-43	49-51	7.5-8.5

A kind of preparation method of 140 ℃ of fuse burn-out core lead-free low-temperature alloys, step is:

⑴ put into metallic tin by weight ratio stainless crucible, is heated to the tin fusing on electric furnace;

⑵ add by weight ratio bismuth metal under 250-280 ℃, fusion clear after, then add indium metal, moltenly add that air release agent is degassed, slagging-off after clear, being cast into diameter is the low-temperature alloy rod of 25mm;

⑶ with the vertical extruder of 100 tons extruding, and extrusion temperature is 70 ℃, and mould is the 5 holes extruding of 25mm, and the low-temperature alloy silk of extruding diameter and be 1.0mm uses as the fusing core of Thermal Cutoffs.

The metallic tin that the embodiment of the present invention is used, indium, bismuth and air release agent are the known products of the industry.

The fusing point that confirms by experiment the alloy prepare reaches 140 ± 2 ℃.

Claims (4)

1. one kind 140 ℃ fuse burn-out core lead-free low-temperature alloys is characterized in that: its raw material consists of and weight percentage ranges is respectively:

Bi：49%-51%；

In：7.5%-8.5%；

Sn: surplus.

2. 140 ℃ of fuse burn-out core lead-free low-temperature alloys according to claim 1 is characterized in that: its raw material consists of and weight percent is not:

Bi：50%；

In：8%；

Sn：42%。

3. the preparation method of one kind 140 ℃ fuse burn-out core lead-free low-temperature alloys, it is characterized in that: step is:

⑴ heat metallic tin, treats the tin fusing;

⑵ add bismuth metal under 250-280 ℃, fusion clear after, then add indium metal, moltenly carry out conventional adding after clear air release agent be degassed, slagging-off, be cast into the low-temperature alloy rod that needs size.

4. 140 ℃ of fuse burn-out cores is characterized in that: with the low-temperature alloy rod that extrusion machine extruding claim 3 prepares, extruding needs the low-temperature alloy of size silk as the fusing core of Thermal Cutoffs.