Experimental study on mechanical properties of Ni/TiO2 FGM processed by pressureless sintering technique

Abstract

In the present work, an experimental investigation and characterization of Functionally Graded Materials (FGMs) is carried out. The Nickel (Ni) and Titanium dioxide (TiO2) materials are taken as principal materials and the powder metallurgy technique is used for the preparation of specimens. The Nickel powder has a particle size of 20 μm with more than 99% purity and Titanium dioxide powder having 35 μm particle size with more than 99% purity is used for this study. The FGM specimens are prepared with five layers, with pure Nickel on one side and pure Titanium dioxide on opposite side of the specimen; and the three intermediate layers comprising of mixture of Nickel and Titanium dioxide. The five layered FGM samples are prepared with one inch diameter round die and the compacted samples are heated up to 1200°C in an inert gas (argon) atmosphere. The microscopic result shows that the microstructure of Ni/TiO2 FGM has varied layer-by-layer and the interface between the layers are observed. As a part of mechanical characterization, both green and sintered FGM sample densities are measured for each layer of the sample. The Rockwell hardness test method is used to find the hardness of the each layer in the samples. Linear shrinkage of the specimen is calculated with the help of green sample dimensions. The Compression test is conducted on the sintered specimens by using universal testing machine; stress-strain behaviour and maximum stress reported.