The mechanical properties of the NiAl/Cr and NiAl/Cr(Hf,Ho) in-situ composites at room temperature are summarized in Table 1. Clearly, with the addition of Hf and Ho, the yield strength, compressive strength and compressive strain all increases obviously. Compared with the increase of strength, the improvement of the compressive ductility is much greater, which increases more than one time. The microhardness tests on the NiAl/Cr eutectic show the Hf and Ho addition increase the hardness of the eutectic structure. Such a change may be attributed to the increase of the interface dislocation, which impedes the movement of the mobile dislocations.
Table 1 Mechanical properties of the NiAl/Cr and NiAl/Cr(Hf,Ho) in-situ composites
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