| The mechanical properties of Ni_(76)Al_(24)-0.5B intermetallic compound by elemental powder process were studied. Benefited with the fine grain structure the hot extruded alloy showed a combination of high tensile yield strength, about 850㎫, and tensile ductility, more than 40% elongation. To improve the strength further, a dispersion hardening was also studied. The strengthening species was selected on the basis of thermal expansion compatibility with the matrix. Based on the thermal stress and strain due to mismatch of the thermal expansion coefficient between the matrix and the dispersoids, we determined ZrO₂as the most suitable species. More than 140㎫increase in the yield strength was obtained with a tensile elongation of 30% by adding 3.2vol% of the reinforcing phase to the Ni_(76)Al_(24)-o.5B matrix. |
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