At different
compression rates TZM alloy fracture morphology is different. TZM alloy which produced by powder
metallurgy has four general fracture mode, along strengthen molybdenum
particles internal fracture, along strengthen phase particles fracture, along
the adhesion and strengthen phase internal fracture, along with enhanced adhesion
particles internal fracture.
By analysis TZM alloy fracture surface under different compression ratio found that the un- rolling TZM alloy fracture mode is intergranular brittle fracture, from the SEM image can clearly see each grain exhibit polyhedral shape and full of voids. In the stretching process, these voids as source of crack and they connect with each other resulting in alloy breaks. When TZM alloy compression ratio is 40% the fracture mode is intergranular fracture and cleavage fracture, where individual grains have fracture phenomenon. At the same time, there are some small spherical particles dots and hollow on the grain boundary fracture. These spherical particles dots are TiC which play dispersion strengthen in alloys, but occurs at grain boundaries will reduce the strength of the grain boundaries to a certain extent. And because equiaxed structure and some do not weld holes exist, so the tensile strength is not high.
By analysis TZM alloy fracture surface under different compression ratio found that the un- rolling TZM alloy fracture mode is intergranular brittle fracture, from the SEM image can clearly see each grain exhibit polyhedral shape and full of voids. In the stretching process, these voids as source of crack and they connect with each other resulting in alloy breaks. When TZM alloy compression ratio is 40% the fracture mode is intergranular fracture and cleavage fracture, where individual grains have fracture phenomenon. At the same time, there are some small spherical particles dots and hollow on the grain boundary fracture. These spherical particles dots are TiC which play dispersion strengthen in alloys, but occurs at grain boundaries will reduce the strength of the grain boundaries to a certain extent. And because equiaxed structure and some do not weld holes exist, so the tensile strength is not high.
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