Influence of boron on mechanical properties of M951 alloy
(1.Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China2.Department of Superalloys, Institute of Metal Research, Chinese Academy of Sciences,Shenyang 110016, China)
Abstract: It is generally agreed that appropriate content of boron is beneficial to mechanical properties of many superalloys. In an effort to improve stress rupture properties of a new superalloy M951, the content of boron is optimized. Stress rupture tests were carried out using a FC-20 high temperature creep testing machine. The micro- structure, fracture surface and dislocation structure were investigated by optical microscopy, scanning electron microscopy and transmitting electron microscopy. The results indicate that the addition of boron improves the stress-rupture life at 1100℃ and 40MPa, but does not affect elongation remarkably. The stress-rupture life is the longest when the content of boron is 0.024%. Boron also enhances the tensile ductility and has no obvious effect on the tensile strength.
Key words: boron； superalloy； M951 alloy； stress-rupture life； ductility