The sintered parts are mainly used for automobile industry, and a part of air conditioners. In automobile industry, the application range of sintered parts is very broad and use for a driving and a lubricating system. And air conditioner uses them for compressor. Grinding of compressor and pump parts is very difficult these days, because these parts use High hardness materials and require high precision grinding. Tool life has to be extended to decrease production cost. We analyzed processing mechanism and developed new grinding wheels for Double Disk Grinding. And, we introduce new truing technology that improved tool-life and precision.
WC/WC interface in VC mono-doped WC-10mass%Co submicro-grained hardmetals of was investigated together with WC/Co interface by using HRTEM and XMA. The thickness of V-rich layer and the analytical value of V at WC/WC interface were almost the same as those at WC/Co interfaces. These results, etc., suggested that the V-rich layers at both interfaces were not generated by an equilibrium segregation mechanism in the sintering stage, but generated by a preferential precipitation mechanism during the solidification of Co liquid phase in the cooling stage. Based on this suggestion, we succeeded in developing a nano-grained hardmetal with 100 nm .
Recently, there has been a remarkable trend of using aggregates at sizes smaller than 13 mm for drainage asphalt pavement (DAP) in order to reduce the noise generated between vehicle tires and road surface. These DAPs have their performance and durability seriously worsen after several years in-service due to the clogging of void space and the abrasion. This paper proposes the use of large size aggregates in porous asphalt mixtures to overcome these defects. Results of laboratory and field experiments on asphalt mixtures with several aggregate gradations are investigated and compared. The study focuses on advantages of DAP using large size aggregate and on particle size combinations containing no fine aggregates of size 2.36 mm or less, which have not been considered in current engineering practice.