Ti matrix composite has attracted much attention because of their potential to achieve higher specific strength than conventional Ti alloys. Titanium boride (TiB) is chemically stable in the Ti matrix and has a small difference in thermal expansion coefficient. Therefore, TiB whisker is particularly promising as a reinforcing filler in Ti matrix composite. TiB whisker-dispersed Ti matrix (Ti-TiB) composite has excellent tensile strength, although its fracture elongation is lower than Ti alloys. Moreover, the fatigue properties of Ti also are improved by controlling the orientation of TiB whiskers. This article explains the strengthening mechanism of tensile and fatigue properties of Ti-TiB composites.

In this study, an Al-(Al₃Ti＋Diamond) functionally graded grinding wheel, a kind of functionally graded material, was fabricated by the centrifugal sintered-casting method, which combines centrifugal sintering and centrifugal casting. A mixture of diamond grains, Al particles, and Ti particles was sintered under the centrifugal force to fabricate a ring-shaped preform. During this process, the exothermic reaction of 3Al＋Ti→ Al₃Ti promoted sintering. The molten Al matrix metal was subsequently poured into the fabricated preform under a centrifugal force (centrifugal casting) to obtain a functionally graded grinding wheel. The drilling performance of the fabricated functionally graded grinding wheel for carbon fiber-reinforced plastic (CFRP) laminates was also investigated using a dual-axis grinding wheel system. Our results show that the Al₃Ti phase acts as a heterogenous nucleation site during centrifugal casting, resulting in a refined and uniform microstructure with enhanced mechanical properties.

In recent years, the use of Al matrix composites with high heat dissipation has grown because of the increased heat generation of high-power semiconductors. These composites must have excellent thermal conductivity, excellent mechanical properties over a wide temperature range, and the ability to suppress thermal expansion. In this study, TiB₂ particles were selected as the additive to pure aluminum, the composites of which were fabricated by sintering. The objective of this study was to clarify the relation between particle dispersibility and thermal conductivity. Initially, TiB₂ particles and Al powder were mixed dry and wet with ethanol to form mixed powders, and 10 vol.% TiB₂ particles dispersed pure Al matrix composites were fabricated using the spark plasma sintering (SPS) process. Subsequently, dispersibility was evaluated using the LN2DRver method, followed by particle size distribution, and thermal conductivity. Consequently, we were able to quantitatively assess the difference in dispersibility caused by the mixing method. Moreover, the experimental thermal conductivity was corrected using the relative density, and a slight difference was noted between wet and dry processes. Furthermore, the relation between dispersibility and thermal conductivity was calculated by simulation. The thermal conductivity increased as the dispersibility decreased, and as the volume fraction of TiB₂ particles in the pure Al matrix increased, the thermal conductivity improved significantly.