Yield anisotropy and tension/compression asymmetry of a Ni3Al based intermetallic alloy

In order to investigate the yielding behavior of the newly developed Ni 3 Al-based intermetallic alloy IC10, yield stresses have been measured in tension and compression with different orientations. The specimens were cut from a sheet with different angles inclined from the solidification direction. The inclined angles were taken to be 0 , 22.5 , 45 , 67.5 and 90 . All experiments were conducted at room temperature except for orientation 0 , whose deformation temperatures ranged from 298 to 1273 K. Experimental results show that the yield strength of alloy IC10 has the anomalous behavior which has been observed for other Ll 2 -long-range ordered intermetallic alloys, but it is less pronounced. The abnormalities show the following characteristics: (i) the yield strength increases as the temperature is raised below the peak temperature, (ii) yield strength anisotropy, (iii) tension/compression asymmetry. Compared to Ni 3 Al single crystals, the polycrystalline exhibits some different yielding behaviors which may be due to the high volume fraction of c phase.     

Ti—48Al合金PST晶体显微组织及高温压缩性能

采用磁悬浮区域熔炼的方法，制备了ＰＳＴ晶体，在８００℃对其压缩性能进行了测试，并对其变形组织进行了观察。结果表明，在８００℃时的屈服强度取决于片层界面与压缩轴的夹角，在＝９０°时屈服强度为最高，而＝４５°为最低。８００°时屈服强度有较大程度的下降，这与α２相中锥面滑移系｛１１２１｝〈１１２６〉的临界分切应力的降低有关。