Ultra high pressure consolidation of ball milled nanocrystalline TiTaNb alloys

Abstract

The effect of increased Ta and Nb additions on the structure of high energy ball milled Ti alloys was studied using X-ray diffraction and high resolution TEM. Ball milled powders were consolidated using ultra high pressure from 4-7 GPa at temperatures of 650-700°C. The microstructure of the compacts consisted of ultra fine grains in the range of 20 nm of α and β phases. Micro-hardness measurements showed very high hardness of ball milled and compacted powders close to 7 GPa (slightly decreasing with the increase of alloying additions) and a decrease in the Young's modulus with the increase of Nb and Ta content i.e. the amount of β phase. © 2007 The Japan Institute of Metals.