Crack initiation behavior of titanium boride whisker reinforced titanium matrix composites during small punch testing

Abstract

TiB whisker reinforced Ti matrix composites are potential aerospace materials due to their outstanding specific tensile properties. However, it is necessary to enhance their fracture toughness for their practical realization. In this study, we investigate the crack initiation behavior on the surface of TiB whisker reinforced Ti-6Al-4 V alloy matrix (Ti6Al4V-TiB) composites under tensile loading during small punch testing. It is revealed that initial cracks of the Ti6Al4V-TiB composite occur from the fracture of TiB whiskers, and these cracks are united after propagating in the β phase of the Ti-6Al-4 V alloy matrix.KEYWORDS metal-matrix composites, crack propagation, Ti-6Al-4 V

Strengthening Mechanism of Titanium Boride Whisker-Reinforced Ti-6Al-4V Alloy Matrix Composites with the TiB Orientation Perpendicular to the Loading Direction

“…Moreover, the percentage of exposed fractured TiB whiskers was larger than the TiB volume fraction. This result indicates that the crack selectively occurred from inside TiB whicker under tensile load, or selectively propagated through the TiB whiskers during the failure of the Ti6Al4V-TiB composites [25,26]. It is implied that this selective crack occasion or propagation inside the TiB whiskers occurs due to the drastic decrease in the elongation of the Ti6Al4V-TiB composites.…”

Effect of TiB Orientation on Near-Threshold Fatigue Crack Propagation in TiB-Reinforced Ti-3Al-2.5V Matrix Composites Treated with Heat Extrusion

“…Prior work has demonstrated that the mechanical properties of stainless steels [15] and of alloys of magnesium [16], cobalt–chromium–molybdenum [17], and titanium [18,19,20,21,22,23,24,25,26,27,28,29,30] can all be improved via the addition of boron. The combination of titanium and boron generates whiskers of titanium boride (TiB) as a result of the reaction Ti + TiB 2 → 2 TiB.…”