图像化的箭头大概分为三种形式。健脾养胃，你可以试试这两个方法忘记你记住爱情免费观看The TiAl alloy powders were prepared by direct diffusion reaction of Ti and Al using titanium powder and aluminum powder as raw materials, and using titanium hydride powder and aluminum powder as raw materials, respectively. The amount of defects increases in the two kinds of raw materials in the process of ball milling due to mechanical forces, and the defects will gradually release energy at the same time to promote alloying in the following alloying process. The alloy powders can be prepared at a relative lower temperature due to direct diffusion reaction of the titanium powder and aluminum powder. By contrast, TiAl alloy powders cannot be got from titanium hydride and aluminum powders at low temperature since the system energy is low due to the low level of defects and that dehydrogenation reaction is an energy absorbing process. So the heating temperature should be raised to make titanium hydride and aluminum powders change to a pure TiAl alloy powder.