| With the development of deep drilling technology in China,the requirement of drilling rig hoisting capacity is becoming more and more highly.Based on the deep hole drill need brake pad material performance requirement,powder metallurgy friction materials is chosen as the brake pad material,deep hole drilling rigs and reference for the domestic high-speed trains and aircraft brake pad materials of powder metallurgy material formula and process,and through the impact on the material of the friction and wear characteristics of each element,through the early experiments selected as rig brake pad material selected formula.By set comparative experiments,changing the particle size of SiO2 and Al2O3,and the matrix group of Cu powder and Fe powder particle size grading,block production materials and physical mechanical properties and friction and wear performance test,study the several groups of size changes affect the performance of block,find the rule of change so as to provide basis for the optimization of formulation.Research shows that:1.Material porosity increase with the particle size of SiO2 and Al2O3 increases gradually,and the effect of SiO2 on the material the void fraction of less than Al2O3 on the influence of porosity in the material.2.With the increase of SiO2 particle size,the material of the friction coefficient,wear rate is also increased.3.With increase of the particle size of Al2O3,material increases the coefficient of friction,and wear rate increased gradually.Because of the Al2O3’s mohs hardness is greater than SiO2,Al2O3’s friction coefficient and wear on the level of the same size quantity is larger than SiO2.4.When the nano-SiO2 and Al2O3 in micron level both add to matrix,nanometer particles will reinforced the copper matrix,micron particles provide higher friction coefficient,the material of higher friction coefficient,wear is reduced. |
