Effect of Fabrication Method and Porosity Content on Elastic Modulus of a Nano-Particle Dispersed Nickel Base Alloy

The change in the elastic modulus of mechanically alloyed MA۷۵۴ Ni-based superalloy as a function of the porosity and fabricating method has been discussed in this study. A mixed powder of a nano-particle strengthened nickel alloy was prepared directly from its alloying elements via mechanical alloying. The mixture then consolidated using two different powder metallurgy methods, pressing was followed by sintering and as was hot extrusion followed by drawing. The powder and solid parts were characterized by XRD, XRF, and microscopic examination. The porosity content and the elastic modulus of the samples were measured via Archimedes, image analysis, tensile, and/or compression tests, respectively. The results indicated that two methods of porosity measurement provided different values for each specimen. In addition, results showed, while processing method has influences on porosity content, it also affects the elastic modulus of the alloy tremendously. Two different values of experimental modulus can be justified by the effect of texture. The different linear and polynomial models are given for different methods of the processing.

Keywords:

Nanoparticle Strengthened Nickel Alloy , Mechanical Alloying , Hot Extrusion , porosity , Elastic Modulus