Study On Brake Material For Deep-Hole Drilling Rig Based On Copper-Based Powder Metallurgy

The rig hoist braking system is a very important part of the full set of drilling equipment,with the deepening of drilling depth,a higher demand has puted forward for its security,and which affect the security of the most critical component is brake materials.current use of brake materials are mainly the traditional asbestos brake materials,at the condition of high temperature,its performance is unstable,and prone to "hot recession" phenomenon.Copper-based powder metallurgy brake material has excellent friction and wear properties and high thermal conductivity are widely used in high-speed rail and aviation and other fields.Using powder metallurgy technology,designed 16 sets of formulas and 16 sets of different sintering processes by the four factors and four levels of orthogonal test,used hot pressing method sintered test blocks,and tested the friction and wear properties and physical mechanical properties,using scanning electron microscope(SEM) observed the surface morphology and the wear scar morphology,finally analysis and discussion the sintering temperature,sintering pressure,sintering time and pressing force,as well as the Fe、SiO2、ZrO2 and C on the performance of brake materials,optimized sintering process parameters:15MPa-850℃-15Min-42MPa and optimal composition:1Fe2SiO22ZrO22C、2Fe1SiO23ZrO22C.The test results show that:Fe has a samller impact on the physical and mechanical properties of brake pads,with the increase of iron content,hardness of the material increased;It also has a greater impact on friction and wear properties of brake pads,with the increase of iron content,the friction coefficient increased rapidly and the wear of coupling material almost no increased. SiO2 has a significant impact on the friction and wear properties of brake pads, with the increase of SiO2 content,the friction coefficient and the wear of coupling material increased rapidly,it content should controlled at about 5%,high levels is easily detached from the matrix. ZrO2 also has a significant impact on the friction and wear properties of brake pads,when its content is more than 4%,the friction coefficient and the wear of coupling material increased rapidly with the increase of the ZrO2 content.With graphite join,it can improve the wear resistance of materials and reduce the wear of coupling materials, with the increase of Cu content,compressive strength and density increase,hardness reduce,so the content of Cu is between 55 percent and 65 percent is appropriate.Sintering temperature has a significant impact on the comprehensive properties of brake pads, With the increase of sintering temperature,the density,strength and hardness reduces,porosity increases;Sintering pressure only has a certain influence on the hardness,with the increase of sintering pressure,hardness first increases and then decreases,when sintering pressure is 20MPa,hardness reaches its maximum; Sintering time only has a significant influence on the compressive strength,with the increase of sintering time, compressive strength increases; pressing force has a significant influence on the compressive strength, with the increase of pressing force, compressive strength first increases and then decreases,when pressing force is 42MPa, compressive strength reache maximum.