Grain boundary fracture in tungsten bi-crystals

Quantitative Microstructure and Defect Density Analysis of Polycrystalline Tungsten Reference Samples after Different Heat Treatments

“…Considering the different fracture behaviour of low and high-angle grain boundaries that was found by Liu et al [12], one can expect also the fracture behaviour of tungsten to change with recrystallization. Indeed, hot-rolled respectively stress-relieved tungsten shows at least some ductility.…”

“…The different grain boundaries within the mapping areas were classified as either low-angle for misorientation 9 angles of 2°   < 10°, respectively as high-angle for   10° (Figure 3a and d). This is motivated by experiments of Liu and Shen [12], who investigated the fracture behaviour of tungsten bi-crystals with a twist boundary. Their analysis showed that a crack initiated perpendicular to the grain boundary bridges the boundary for small misorientations .…”

Fabricating high performance tungsten alloys through zirconium micro-alloying and nano-sized yttria dispersion strengthening

“…However, polycrystalline W has a high ductile-to-brittle transition temperature (DBTT) of about 800°C. A major cause of the low toughness of W alloys is their sensitivity to some impurities such as O, N and P, which segregate on the grain boundaries (GBs) and decrease the GBs cohesion [6][7][8][9]. Therefore, methods that modify impurities distributions and strengthen GBs would be effective in improving the strength and toughness of tungsten.…”

Micro-mechanical measurements of fracture toughness of bismuth embrittled copper grain boundaries

“…However, measuring the mechanical properties of individual boundaries is difficult. Much previous work has used specially grown bi-crystals [1,2]. This is time consuming and expensive, and limits the materials and types and number of grain boundaries which can be studied.…”