| 摘要 |
A method of making a bearing or bearing material of polyethylene, lead monoxide and ammonium manganese phosphate comprises the crushing or powdering of the above ingredients in given proportions such that at least 50% of each of the powders will pass through a 200-mesh sieve. After thorough mixing the combined powder is pressed in a suitable die at a pressure above 2,000 lbs./sq. in. to form short cylinders of initially pressed material. This material is then broken up and ground to a size capable of passing through a 10-mesh sieve. The subsequent powdered material is then pressed in a suitable die at a pressure between 2,000 and 20,000 lbs./sq. in., to forms of desired shape. The dies in this pressing operation being preferably maintained at a temperature of between 110 DEG and 130 DEG C. and the subsequent forms obtained are then sintered in an oven at a temperature between 140 DEG and 200 DEG C. (preferably about 170 DEG C.). The components thus obtained may require little or no finishing operations. Another method may be as described with the exception that the second pressing operation may be at room temperature and at a pressure of 70,000 lbs./sq. in. The initial pressing and grinding operations tend to improve the homogeneity of the final product and reduces the tendency of components to crack during sintering. Specification 936,741 is referred to. |
