Development of graded heat-resisting Ti base material by gas-deposition

钛铝化物具有高达1000摄氏度的优异性能，有望成为高温材料。例如，它的强度随着温度的升高而增加，并且在高达900摄氏度的温度下保持相当好的抗氧化性。但其室温延展性较低，是导致其在实际使用中可靠性不高的主要原因。本研究的目的是通过气相沉积的方法，开发一种介于铝化钛高温侧和钛合金低温侧之间的梯度成分的材料，以弥补铝化钛的低延展性和降低热应力。气沉积系统有三个腔室，两个腔室用于铝和钛的蒸发，一个腔室用于铝和钛细颗粒的沉积。通过本研究阐明了钛铝的蒸发和级配条件。

Titanium-aluminide is expected as a material for high-temperature use because it has the excellent properties up to 1000 degrees centigrade. For example, it increases strength with increase of temperature and keeps fairly good resistance to oxidation up to 900 degrees centigrade. However, the main reason not to get the reliability for actual usage is its low ductility at room temperature.The aim of this study is to develop the material that has the graded composition between the high temperature side of titanium-aluminide and the low temperature side of a titanium alloy so as to make up for the low ductility of titanium aluminide and reduce the thermal stress by gas deposition method.Gas deposition system has three chambers, two chambers are for evaporation of aluminum and titanium and one is for deposition of aluminum and titanium fine particles.The conditions of evaporation and gradation of titanium and alminum are elucidated through this study.