The Influence of Constituents and MA Conditions on the Mechanical Properties of Ni₃Si Intermetallic Compounds

Abstract

Ni₃Si intermetallic compounds have an excellent corrosion resistance in sulphuricacid solution. However, production of these compounds was difficult because of poor ductility caused by formation of a very brittle phase. In order to suppress formation of the brittle phase, process conditions involving a mechanical alloying(MA) method have been investigated for the production of Ni₃Si intermetallic compounds. First, fine Ni-Si composite powders prepared by the MA method were hot extruded. Then Ni₃Si intermetallic compounds were obtained by a particular heat treatment. Influence of the constituents and the MA conditions on mechanical properties of the Ni₃Si intermetallic compounds were investigated. As a result, in 13.1 mass%Si- 86.9 mass%Ni materials, tensile strength improved as MA time became longer, although the material had poor ductility. When the Si content was reduced below 13.1 mass%, the tensile strength improved and ductility increased. The critical Si content for achieving of ductility was 12.2 mass%Si.