A kind of powder metallurgic method is produced silicon carbide aluminum matrix composite binding agentTechnical field
The present invention relates to a kind of binding agent, particularly a kind of powder metallurgic method is produced silicon carbide aluminum matrix composite binding agent.
Background technology
Silicon carbide aluminum matrix composite is owing to having the excellent over-all propertieies such as high, good stability of the dimension less than strong, Gao Bimo, high temperature resistant, wear-resisting, antifatigue, thermal expansivity, in the fields such as aerospace, military project, automobile, have a extensive future, become the advanced composite material of domestic and international primary study exploitation.The preparation technology of silicon carbide aluminum matrix composite has multiple, but up to the present, the method for comparative maturity has powder metallurgic method, casting, spray deposition, extruding osmose process and vacuum suction casting technique.But the most frequently used and the most competitive method is powder metallurgic method.First silicon-carbide particle and crystallite Al alloy powder are evenly mixed by a certain percentage, make composite blank, with mould, through coldmoulding, be then heated to that vacuum is carried out in solid-liquid two-phase region or matrix material ingot bar is made in atmosphere hot pressing, then make section bar and part through secondary processing.
Powder metallurgic method is produced silicon carbide aluminum matrix composite, composite blank needed with binding agent, composite blank to be processed before mould cold pressing forming process, to guarantee silicon-carbide particle and the equally distributed consistence of crystallite Al alloy powder, prevent because of matrix material each other the difference of proportion cause component separated, binding agent is produced in silicon carbide aluminum matrix composite and is played a very important role in powder metallurgic method, the quality of binding agent, will directly affect the performance of product.The binding agent using at present has to adopt take that multipolymer that ethene and propylene be monomer component forms, have to adopt under room temperature and be the epoxy resin of liquid and have a solidifying agent that is selected from the functional group of amino, carboxyl at least, using toluene or acetone as solvent, these binding agent height are flammable, mix with crystallite Al alloy powder the danger that has fire and blast, and boiling point is high, easily residual, when sintering is heated to solid-liquid two-phase region, product is easy to foaming, cracking, have a strong impact on the yield rate of product and the physicals of product, and the gas serious environment pollution of when heating volatilization.
Summary of the invention
The object of this invention is to provide that a kind of boiling point is low, sintering character good, the powder metallurgic method of environmentally safe produces silicon carbide aluminum matrix composite binding agent.
Binding agent of the present invention is dissolved in respectively glycerine ((CH2-OH) 2CH-OH) solvent by vegetable-protein (vegetable protein), shellac (Laccifer lacca), polyurethane adhesive (polyurethane) and forms, its vegetable-protein: shellac: polyurethane adhesive: the mass ratio of glycerine is 8:14:3:75.During use, the mass ratio of binding agent of the present invention and complex alloy powder granulation blank consumption is 1:5 ~ 10, in this ratio, mix, being heated to 45 ℃ stirs to bonding shape, caking ability can bond under external force, and agglomerating also to make it be separated into suitable, with mould, through coldmoulding, then obtain silicon carbide aluminum matrix composite through super-dry, sintering.
Embodiment
By mass fraction, get respectively 8 parts of vegetable-proteins, 14 parts of shellac, 3 parts of polyurethane adhesives, by it, to dissolve in respectively in order mass fraction be in the glycerine solvent of 75 parts and stir; The binding agent modulating and complex alloy powder granulation blank are mixed by the mass ratio of 1:8, be heated to 40-60 ℃ and be stirred to thick.
Binding agent boiling point of the present invention low (330-350 ℃), glycerine solvent boiling point is 290 ℃, under normal temperature state, adhesive property is good; After the heating of binding agent composition, easily discharge, do not affect composite property, and can increase wettability, effectively improve Composite Sintering performance.Its cohesive strength is very large, environmentally safe.