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The paper deals with the end-milling machinability of α-β titanium alloy (Ti-6AI-4V alloy) by new PCD (Polycrystal-line Diamond) cutting tools at high cutting speeds in order to develop a new technology for a high productivity titanium finishing. The main focus of this paper is on investigating the relationships among cutting conditions, PCD tool materials, and tool wear. It was found that the edge engagement time of cutting tools with titanium workpiece has a great effect on PCD tool wear. Compared to cemented carbide tools, PCD tools have a longer tool life, especially at higher cutting speeds. The geometric shape of cutting edges and tool material greatly influences the performance of PCD tools in cutting titanium alloy.

ABS sensor rings for automotive use are becoming smaller and thinner because of the demand for low cost and light weight. Such small thin parts are easier to break as they must withstand the same severe conditions as larger heavier parts. Superior elongation properties, after corrosion testing, are necessary for avoiding breakage and to obtain superior corrosion resistance. We have, therefore, developed such high performance P/M stainless steel with superior elongation and corrosion resistance. Conventional stainless steel has uniform pores on its inner surface which makes allows water penetration thus making corrosion worse and decreasing elongation. It is possible to increase corrosion resistance by changing pore structure (e.g. decrease continual pores) through the addition of special alloys that accelerate the sintering process.

An internal gear-type pump has advantages compared with an external involute gear-type pump, for example, higher mechanical or volumetric efficiency, considerable reduction of weight and dimension in the oil-pump system[1]. This paper presents characteristics of the internal gear type rotors with a modified trochoidal profile in the oil-pump system, and new P/M(Powder Metallurgy) aluminum alloys which satisfy required wear properties as the lubrication oil-pump rotors. Also, the advantage of high volumetric efficiency and discharge performance and excellent properties of the oil-pump rotor with a modified trochoid profile were combined with a R/S (Rapidly Solidified) aluminum alloy in the scavenging pump for racing car engine. Good results without wear or damage after an actual race are also reported.

The joining process of silicon nitride (S13N4) turbine rotor and steel metal shaft was investigated. The process consists of brazing procedures with multi-layer metallizing and complementary steps involving shrink fitting and non-destructive tests. In the course of the brazing steps, preliminary investigations using small specimens were conducted on the formation of a highly strengthened interface at high temperature and thermal stress reduction, and superior high temperature strength and heat cycle resistance were obtained. Rotary tests at high temperature were successfully completed using the rotor joined by this process.

We have developed new P/M Al-Si wrought alloys having high strength and high wear resistance for use in the rotors and vanes of rotary car air conditioners. In addition, combined with the development of near-net-shape extrusion technologies, through a joint project with Diesel Kiki Co.,Ltd., we have succeeded in the world's first mass production of rotors made of P/M aluminum wrought alloy. In this paper, the properties and production technology of vanes and rotors made with new P/M Al-Si wrought alloys are presented.

Recently, SiCr clean steel wire for springs on automotive engine valves has been developed. This report describes the characteristics of valve springs subjected to a new manufacturing process using SiCr clean steel wire. The process developed by the authors is as follows: First, form a helical spring with SiCr clean steel wire. Next, quench using the distortion preventing technic --Marquenching--. Temper at a temperature lower than the conventional temperature. Shot peen to the surface layer of the spring. And lastly, polish electrolytically to remove micro surface defects formed through shot peening. Using this new manufacturing process, a valve spring with high fatigue resistance can be produced. At the test stress of 588MPa(τm)±490MPa (τa), the number of cycles to fracture was above 100 million, while the number of cycles to fracture was 4 million using the conventional process with the SiCr clean steel which has the best fatigue resistance for commercial use.