Solid Solution Hardening of Nickel —Role of Transition Metal and B-subgroup Solutes—

Yoshinao Mishima, Shouichi Ochiai, Noboru Hamao, Masayoshi Yodogawa, Tomoo Suzuki
1986 Transactions of the Japan Institute of Metals  
A systematic investigation is made on the solid solution hardening of binary nickel alloys with additions of B-subgroup and transition metal elements. The 0.2% flow stress at 77 K and the Young's modulus are measured for a variety of binary alloys to evaluate the rate of solution hardening per one available data on the rate of change in lattice constant (da/dc), interpretation of the solution hardening subgroup elements is linearly related with a combined parameter appropriate for the elastic
more » ... e for the elastic interaction between solutes and edge dislocations, where the contribution of modulus misfit is minimal and atomic size misfit governs the hardening. It is also found that for the additions of transition metal elements there is an extra hardening over what is expected from the same treatment on B-subgroup elements. These findings are the same in nature as what has been observed in the solution hardening of an Ll2 intermetallic compound Ni3Al. The reason for the extra hardening by transition metal elements is discussed, and a possible contribution of electronic interaction involving d-electrons is suggested for the solution hardening by a transition metal solute in the transition metal solvent, nickel. In the preceding paper, the solid solution hardening in Ni3Al has been investigated for ternary additions of B-subgroup and transition metal elements(1). It has been found that the solution hardening in the compound can not be interpreted for both types of alloying elements together by a single expression for the elastic interaction. Namely, it has been shown that the hardening is more intense by the additions of transition metal elements than by the additions of B-subgroup elements where the hardening is linearly related with a combined parameter for the interaction between solute atoms and edge dislocations. Then the necessity is raised to carry out the similar type of investigation on the solution hardening of nickel in order to clarify whether the anomalous hardening effect is inherent in the Ll2 crystal structure of Ni3Al or in the majority component of nickel. Technological interest in nickel alloys has often centered on improving the heat resistant properties such as high temperature strength and creep strength by making alloys multicomponent. For this purpose, the additions of transition metals are generally accepted. Prominent examples are the modifications of commercial superalloys, in which the additions of those elements have been properly chosen utilizing regression analyses. As a more fundamental approach, the solid solution hardening has been studied in nickel binary alloys by a number of workers(2)-(9), however, the alloy
doi:10.2320/matertrans1960.27.656 fatcat:sfovdzogzrcqrbaxn5deugs7se