Fe-40wt% TiB2 nanocomposites were fabricated by mechanical activation and spark-plasma sintering of a powder mixture of iron boride (FeB) and titanium hydride (TiH2). The powder mixture of (FeB, TiH2) was prepared by high-energy ball milling in a planetary ball mill at 700 rpm for 3 h followed by spark-plasma sintering (SPS) at various conditions. Analysis of the change in relative sintered density and densification rate during sintering showed that a self-propagating high-temperature synthesis reaction occurs to form TiB2 from FeB and Ti. A sintered body with relative density higher than 98% was obtained after sintering at 1150°C for 5 and 15 min. The microstructural observation of sintered compacts with the use of FE-SEM and TEM revealed that ultrafine particulates with approximately 5 nm were evenly distributed in an Fe-matrix. A hardness value of 83 HRC was obtained, which is equivalent to that of conventional WC-20 Co systems.

In this study, the combined effect of Zr and Si on isothermal oxidation of Ti for 25 and 50 h at 820°C, which is the temperature related to exhaust valves operation, was investigated. Si addition into Ti-5mass%Zr alloy led to a distribution of silicide Ti5Si3 phase formed by a eutectic reaction. The Ti sample containing only Zr showed more retarded oxidation rate than Ti-6Al-4V, the most prevalent Ti alloy, at the same condition. However, while a simultaneous addition of Zr and Si resulted in greater increase of oxidation resistance. The oxide layer formed after the addition of Zr and Si comprised TiO2, ZrO2, and SiO2.

The β-phase Titanium (β-Ti) alloys have been under the spotlight in the recent past for their use as biomedical prosthetic materials owing to their excellent properties such as low elastic modulus, high corrosion resistance and tensile strength. Recently, Niobium (Nb) has gained a lot of attention as a β-phase stabilizing element in Ti alloys to replace Vanadium (V) due to its excellent solubility in Ti, low elastic modulus and biocompatibility. In this work, low cost Ti-20Nb binary alloy has been fabricated via powder metallurgy procedures. The blended powder mixtures of Ti and Nb were sintered at 900°C for 20 mins by the Spark Plasma Sintering (SPS) with an applied uniaxial pressure of 40 MPa. The heating rate was fixed at 50°C/min. The sintered alloy was subject to heat treatments at 1200°C in vacuum condition for various time durations. The characterizations of microstructure obtained during this process were done using FE-SEM, EDS and XRD. By increasing heat treatment time, as understood, the volume of residual Nb particles was decreased resulting in accelerated diffusion of Nb into Ti. Micro hardness of the alloy increased from 340 to 355 HV with the increase in β phase content from 30 to 45%. The resultant alloys had relatively high densities and homogenized microstructures of dispersed lamellar β grains in α matrix.