Combustion Synthesis and Characterization of Porous NiTi Intermetallic for Structural Application

Abstract

This paper describes experimental investigation of thermal and combustion phenomena as well as structure for self-propagating combustion synthesis of porous Ni–Ti intermetallic aimed for structural biomedical application. The objective is to correlate processing conditions with structure for the porous material. Ni–Ti mixture is prepared from elemental powders of Ni and Ti. The mixture is pressed into solid cylindrical samples of 1.1 cm diameter and 2–3 cm length, with initial porosity ranging from 30% to 42%. The samples are preheated to various initial temperatures and ignited from the top surface such that the flame propagates axially downwards. The flame images are recorded with a motion camera as well as the temperature profile. The samples were then cut using a diamond saw in both longitudinal and latitudinal directions. Image analysis software was then used to analyze the porosity distribution in each sample. The porosity distribution was then systematically correlated with the input processing conditions.