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Powder Synthesis, Sintering Kinetics, and Nickel‐Activated Pressureless Sintering of Ti 3 AlC 2
Author(s) -
Panigrahi Bharat Bhooshan,
Gracio Jose J.,
Chu MinCheol,
Cho SeongJai,
Reddy N. Subba
Publication year - 2010
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/j.1744-7402.2010.02572.x
Subject(s) - materials science , sintering , pressureless sintering , nickel , kinetics , metallurgy , chemical engineering , physics , quantum mechanics , engineering
This work aims to produce Ti 3 AlC 2 powder via a new route that consists of two‐step processes, and studies the sintering kinetics and effect of nickel addition on the pressureless sintering behavior of Ti 3 AlC 2 powder. Ti 3 AlC 2 powder of about 5 μm was produced using TiC x and Al powder. Relative density of about 97.6% was achieved using 1 wt% nickel as a sintering aid. Ti 3 AlC 2 powder shows two different activation energies (AE) of sintering, 347 ± 4 and 183 ± 8 kJ/mol at lower and higher temperature ranges, respectively. These AE were found to be matching closely with the AE of Al diffusion in the Ti–Al binary system reported in the literature, indicating that the sintering of ternary Ti 3 AlC 2 ceramic was controlled by the diffusion of Al atoms. When nickel is added, Ni reacts with Ti 3 AlC 2 , tends to decompose it, and forms Ni‐based compounds and liquid phase. Nickel was found to suppress the grain growth of Ti 3 AlC 2 significantly. Sintered sample exhibited a Vickers hardness of 3.2 GPa at a load of 10 N.