Effects of SiC Nanoparticles on the Properties of Titanium-Matrix Foams Processed by Powder Metallurgy

Metal-matrix foams are used widely for structural applications such as impact energy absorption, vibration resistance and weight reduction. In this study titanium nanocomposite foams with different porosity percentages were produced using TiH2, as foaming agent, by powder metallurgy technique. At first, raw materials including titanium powder and different weight percentages of SiC nanoparticles were mixed and then different amounts of TiH2 were added to the mixture. The mixture was compacted at 200 MPa. The samples were heat treated in two stages, first at 400 degrees C for 1 h, as a partial sintering, and then at 1050 degrees C for 2 h, as foaming treatment. Mechanical and structural properties such as compressive strength, energy absorption, porosity percentage and relative density of samples were measured and compared together. Thermo gravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed on foaming agent and samples. The results showed uniform distribution of SiC nanoparticles in titanium matrix and also homogenous pore structure. It was concluded that with increasing SiC weight percent, relative density is increased to 0.43 in the sample with 1.5 wt % SiC. Besides, the measured compressive strength of samples was in the range of 14.4-32.3 MPa. Moreover, it was concluded that the energy absorption of samples increases with increasing SiC nano particles up to 33.09 MJ/m(3).