Search

The contemporary aspects of ultra precision machining of Si3N4 with regards to enhanced productivity and precision demands is presented in this paper. This paper reviews the literature on machining technology of covering the history, Several machining methods of Si3N4 are discussed. By comparing their advantages and disadvantages, some beneficial conclusions, which have some guiding significance for the coming practical works, are reached.

Cracks is frequently generated in crown gear of main reducer of big modulus used in heavy duty truck after carbonizing and quenching. The heat treatment process and the pre-heat treatment before carbonizing, the carbonization process parameter and the quench treatment, all of which influence the component, structure and stress of the gear. In this paper, metallographic examination of the gear was taken after heat treatment with different process parameter, and the reasons that caused cracks in the 22CrMoH steel crown gear used in heavy duty truck after heat treatment was discussed. And strategies and methods are proposed as well.