3D Network structure improvement of TiN and its properties by adding Al powder in SUS316L based Metal Matrix Composite

Abstract

AISI stainless 316L reinforced with 3D network structure with TiN composite by adding Al powder had developed in order to improve interconnectivity of TiN network structure. The composite was fabricated by mixing three different kinds of powders (SUS316L, TiN, Al). During fabrication process, alumina phase occurred due to addition of Al powder in 316L steel matrix. It is known that alumina phase in TiN forms incoherent interface, but when it forms between TiN-TiN, it also improves connectivity of TiN itself by using 3D imaging reconstructing technique (ROBOMET-3D). Alumina phase specifically reduces the void fraction while its formation. Two different experimental approaches: heat treatment and dipping in molten 316L that were able to assist network structure of TiN was also evaluated. The trend of decreasing the void fraction with increasing TiN network interconnectivity was measured. Finally, in order to evaluate the mechanical properties of TiN network interconnectivity, hardness was determined by nanoindentation test and bending test was performed. When alumina is produced due to the addition of aluminum and dipping on molten SUS316L, the composite material not only improves the internal connectivity of the TiN network structure but also reduces the void fraction; which eventually tells that mechanical property of composite material has been enhanced.