Effect of cooling rate on β→α transformation during quenching of a Zr-0.85Sn-0.4Nb-0.4Fe-0.1Cr-0.05Cu alloy

The effect of β→α cooling rate during quenching on a new Zr-Sn-Nb-Fe-Cr-Cu alloy is reported.The microstructure evolution is well characterized by electron channeling contrast(ECC) imaging and transmission electron microscopy(TEM) techniques.The results show that specimens cooled by water,liquid nitrogen,air and furnace from β-phase present martensitic,coarse basket-weave,parallel-plate and lenticular structure,respectively.Residual β phase is detected by performing electron diffraction and composition analysis in the furnace cooled specimen.Micro hardness values of specimens decrease while the width of α laths increase with the cooling rate decreasing.The preliminarily established quantitative relationship among the cooling rate,microstructure and mechanical properties will shed light on the microstructure control and property optimization.