The Formation of Composite Nitride by the Nitriding of the 60 Titanium-40 Vanadium and 80 Titanium-20 Vanadium Alloy Powder

Abstract

Nitridings of 60 Ti-40 V and 80 Ti-20 V (wt%) powder in N2 (1 atm) atmosphere were carried out at 700-1390°C and the nitriding processes were investigated by a gravimetric method, X-ray diffractometry, X-ray microprobe analysis and microscopic observation. The results obtained were summarized as follows.
( 1 ) In the nitridings of 60 Ti-40 V and 80 Ti-20 V powder specimens (grain size is nearly 80 mum), (Ti, V) N single phases were obtained at 1300°C and at 1390°C, respectively.
( 2 ) Ti-rich nitride and V-rich alloy were observed at the initial nitriding stage. But the both phases reacted to form a (Ti, V)N single phase at high temperature as the nitriding proceeded further.
( 3 ) The grain size of Ti-rich nitride were larger in high Ti alloy than in low Ti alloy, so that a (Ti, V)N single phase was formed easily in low Ti alloy.
( 4 ) The rate of nitriding followed the parabolic, law at the initial stage. 60 Ti-40 V alloy was nitrided more rapidly than 80 Ti-20 V.