The Study On Copper-based Powder Metallurgical Friction Material For Deep Hole Drilling Rig

As one of the main part of the drill rig, hoister bears the work of lifting drill pipes, which is the key feature in the drilling process. The improving of the capacity of drilling rigs is limited by the lifting capacity, and the property of the brake material is restricted to the main factors of deep-hole drilling rig. Base on the properties that deep-hole drilling rig need and the existing brake materials, copper-based powder metallurgy brake material was chosen as a brake material of deep-hole drilling machine. Refer to the domestic element formulations of powder metallurgy friction material of high-speed trains and airplane brake materials, and through the investigation on effects of friction and wear characteristics of elements, a formula element of brake materials used by a drilling rig was established. Though orthogonal test ratio, changing content of Cr, SiC and graphite, some material sample was made and the physical and mechanical properties and friction and wear properties was tested. Several elements effect on the performance of test blocks was studied. Also, metallographic analysis by microscope is used to study their effect mechanism, in order to get optimal content of component in the brake materials.The study results include:1. With the increase of sintering pressure, porosity of the material reduced. So the sintering pressure should increase on die under the bearing capacity of die, suppress to the design height, reducing the porosity of the material. With the growth of soaking time, the porosity of the test block will be gradually reduced, but there is little effect on the hardness of the test block.2. The porosity of test block decreased with the increase of the chromium content. Among them, during the change from 2% to 3%, the reduction of porosity was greater. However, in the changes from 3% to 5% of chromium content, with the increase in chromium content, the change of porosity is smaller. Hardness of materials decrease with the increase of chromium content, during the change from 2% to 3%, the reduction of material hardness is larger than the process change from 3% to 5%. Along with the increase of Cr content, friction coefficient of the material increase gradually.3. Add SiC reduces the porosity of the material. With the increase of SiC content, micro-hardness of the material has increased. Along with the increase of the content of SiC, the friction coefficient first increases, then decreases.4. With the increase of graphite, the increase of graphite reduces the micro-strength of materials. Along with the increase of the content of graphite, the friction coefficient first increases, then decreases.