Sadayuki Nakamura

Development of Free Machining Titanium Alloy Connecting Rods for Passenger Cars.

Some fundamental research on alloy design of new titanium alloy and process design such as forging and surface treatment were carried out in order to develop new titanium alloy connecting rods. Free machining Ti-3Al-2V alloy is the best alloy for connecting rods because it has the mechanical properties equivalent to quenched and tempered medium carbon steel, a popular material for connecting rods. The alloy can be machined at higher speed than the most popular titanium alloy Ti-6Al-4V. Forging in the β phase temperature range is desirable to enable one heat forging of connecting rods and to eliminate crack initiation. New technology such as induction heating in forging and coating on large ends was developed. As a result of this research, new titanium alloy connecting rods which can be applicable to mass production have been developed.