The Experiment Investigation Study On Pretreatment Friction Components Of Copper-based Powder Metallurgical Friction Material

This work is based on the current rapid development of deep drilling technology,the urgent demand for drill high-performance brake pad materials,carrying out the development preparation of high-performance brake friction material.We will use a new type of friction material of powder metallurgical friction materials instead of traditional asbestos friction material.This method draws on the development of the formula and process of high-speed trains and aircraft brake pads powder metallurgy friction materials at home and abroad.Considering the actual working condition of drilling,and the condition of high speed,overload,high temperature environment,the method can still maintain good friction and wear properties of the brake material.Using Al₂O₃ Strengthening copper powder as the base material of powder metallurgy friction materials.Adding iron powder and high melting point metal alloy to strengthen matrix.Choosing four characteristics friction components,And through the pretreatment by sulfide,Made A,B,C,D,E five formula,Hot Pressed Sintering,the production materials and physical mechanical properties and friction and wear performance test is blocked.Analysing of friction occlusion mechanism between friction composition and matrix group.Observe the mechanical combination of dissolution and diffusion,which is formed by chemical reactions between the distribution of fusion at the border.the cause of different friction performance is explained,so as to optimize the original formula improvement.Studies have shown that:1.Studies have shown that,friction coefficient decreases with the decrease of porosity.2.The friction composition which has S-append processed and metal matrix has a good bonding,Friction surface generated sulfide is a kind of effective components of solid lubricant,distribution in friction components around,involved in friction surface at any time,Friction block can reduce the Mosaic effect,wear is reduced.3.By comparing A sample and B sample,Material porosity increased by friction composition which has S-append processed,4.Containing Al₂O₃,tungsten carbide and carbon ferrochrome powder metallurgy friction materials in friction process occurred serious peeling wear,Fall off the chip so as to facilitate the formation of continuous mechanical mixing layer, although the friction coefficient under the condition of slightly decreased,but the wear is greatly reduced,reduced from 1.1 g to 0.5 g.5.From the point of view of the microstructure,Most of the Mo atomic out of the decomposition of MoS₂ into the iron,Enhancing the matrix strength.6.Added in the matrix of MoS₂ as lubricant can reduce the friction coefficient of friction material,however MoS₂ as spray coating in friction around the particles,it can increase the friction coefficient of friction materials.Effectively reduces friction components of dual hard scratch,prolong the service life of dual pieces.