Powder Metallurgy Route for the Synthesis of Multiprincipal Element Alloys Sputtering Targets

Sputter deposition of multiprincipal element alloys (MPEAs) is a relatively new field of research with high functional potential. The multicomponent design space is immense and practically unexplored. An important obstacle for academic research of such sputtered films is the availability of single-alloy targets and technical difficulties in using cosputtering of multiple metal targets or powder targets. This article focuses on the development of a simple powder metallurgy route, including cold uniaxial pressing of powder mixtures followed by pressureless sintering, for the preparation of targets made of two common base alloys forming simple solid solutions, i.e., FeNiCrCo and FeNiCrMn. In addition, targets of the former one containing 10 at% Al are also prepared. The sintered pellets are composed of randomly oriented crystallites with face-centered cubic structures and an optimum chemical homogeneity. Oxide inclusions and residual porosity, inherent to consolidation and sintering of metal precursors, are observed and possible solutions to overcome these challenging problems are discussed. Nevertheless, encouraging results from preliminary deposition tests of FeNiCrCoAl0.4 using both direct current magnetron sputtering (DCMS) and high-power impulse magnetron sputtering (HiPIMS) are presented.