Abstract
This paper presents a study on the surface durability of sintered metal gears. Gear blanks made of partially prealloyed steel powders were compacted and sintered under various processes, then they were hobbed and case-hardened. Some gears were surface-rolled under various amount of rolling before case-hardening. The contact fatigue tests were carried out for these gears using the power-circulating-type gear test machine. The effects of sintering processes and rolling on the surface durability and wear of sintered metal gears were determined. Furthermore, the surface durability of the above-mentioned sintered metal gears was compared with that of the wrought steel gears. The density of sintered metal gears increases by adopting a double-press-double-sinter (2P2S) process as the sintering process. The surface density of the sintered metal gears tends to increase with rolling for the case of gears with relatively lower density. The surface durability of sintered metal gears tends to increase with an increasing surface density. The surface durability of sintered metal gears may approach that of the wrought steel gears by adopting the appropriate sintering and rolling processes.
