Abstract:

Powder Metallurgy is a novel manufacturing process producing components having desirable characteristics, without subsequent machining, re- sulting in reduced cost and time. In this study, the fabrication of sintered gear and its subsequent case hardening by gas carburizing is mentioned. To under- stand the effects of carburizing on the sintered gear, both the sintered and car- burized specimens were analyzed for its microhardness, breaking load, wear rate and microstructure. The results of microhardness analysis of the carburized gear provides the depth of effective hardening to be 1.02 mm. This increase in hardness caused a minimal reduction in elasticity, causing the ultimate com- pressive strength to decrease from 40 KN to 34.4 KN. The specific wear rate (m3/Nm) was low for sintered material than carburized material, under increas- ing loads and disc speeds. This was contrary to the specific wear rate for in- creasing track radius, where the carburized specimen exhibited better wear re- sistance than sintered specimen. The images obtained from Scanning Electron Microscopy (SEM) for carburized specimen showed relatively uniform grain size and lesser pores than sintered specimen. The carburizing process was found to be beneficiary for gears used for continuous and heavy loads.


Keywords: Gear, Powder Metallurgy, Carburizing, Microhardness, Wear, Mi- crostructure.;