Effect of Multi-Elements Substitution on the Mechanical Properties of Intermetallic Compound

Abstract

<jats:title>ABSTRACT</jats:title><jats:p>It is well known that various elements substitute for a certain sub-lattice of intermetallic compounds. There have been various experimental investigations of the effects of substituted elements on mechanical properties, however, there are few reports describing the effects of multi-element substitution. In the present study, L1<jats:sub>2</jats:sub>-type compounds A<jats:sub>3</jats:sub>B (Ni<jats:sub>3</jats:sub>Al and Co<jats:sub>3</jats:sub>(Al,W)) were selected as model compounds because their substitution behavior is well known. It was reported that various elements such as Ni, Co, Cu, Pd and Pt occupy the A-site, whereas Al, Si, Ga, Ge, Ti, V, Nb, Ta, Mo, and W occupy the B-site. These elements are expected to introduce local lattice distortion, which may affect the motion of dislocations over a wide range of temperatures. Several alloys composed of five or more elements including Ni, Co, Al, Mo, and W, were prepared using an Ar-arc melting machine and heat-treated. Several alloys were found to include an (Ni, Co)<jats:sub>3</jats:sub>(Al, Mo, W, …)-L1<jats:sub>2</jats:sub> compound as a constituent phase. The nano-hardness of these L1<jats:sub>2</jats:sub> phases was higher than that of the high-strength Co<jats:sub>3</jats:sub>(Al,W)-L1<jats:sub>2</jats:sub> compound, confirming that multi-element substitution is an effective way to improve the mechanical properties of an intermetallic compound without decreasing the phase stability.</jats:p>