Katsuya Uchino

Study on the Composition Graded Cemented Carbide/Steel by Spark Plasma Sintering

Abstract: Steel coated with high wear–resistant and high corrosion–resistant hard materials are widely used, but these composite materials do not always achieve the aimed properties, mainly because coating materials with high hardness could not be applied thickly and also could not be jointed firmly as desired. To overcome these problems, the new functionally graded materials were studied. To relieve the thermal stress, Co composition graded cemented carbide powders stacked in multiple layers on steel substrate were sintered and joined on the steel by the Spark Plasma Sintering. Because of low–temperature and short–time sintering, the graded composition of cemented carbide was maintained as desired and a crack– and peel–free coated product could be achieved by this process. From this study, we confirmed that it is possible to realize a high wear–resistant cemented carbide/steel composite material for practical use.

ACE coat™ AC15 alumina-coated cutting tool for highly efficient machining

Abstract Recent changes in the world economy and industrys rapid shift to varied, small-quantity production demands cutting tools with even higher efficiencies. Conventionally, the efficiency of cutting tools has been improved chiefly by increasing the cutting speed. However, since high cutting speed significantly shortens tool life, there arises an increasing interest in high feed rate machining. In answer to this trend the AC15 alumina-coated cutting tool has been introduced, which is capable of high feed rate machining. It uses a newly-developed substrate with a functional gradient composition, which allows the tool to have a significantly improved breakage resistance while maintaining plastic deformation resistance. In addition, the alumina-coated tool tip assures high wear resistance at high feed rates. The AC15 is a highly versatile tool designed for use in every conceivable situation of steel machining. The chip breaker (bumpy sun breaker) was developed, taking full advantage of the characteristics of the AC15, and is intended to provide a new environment for cutting tool applications.