The Effect of Cooling Rate on Microstructure and Mechanical Properties of the Zr-4Hf-3Nb (wt%) Alloy

The mechanical properties of Zr-based alloys, such as strength and elongation, are heavily dependent on the cooling rate during heat treatment. Understanding phase transformation microstructural evolution in various media can establish connection between properties. effect phase, microstructure, tensile Zr-4Hf-3Nb (wt%) alloy is studied this paper. results show that composition samples transforms from α+β to α+β+ω, and, finally, α+α’+ω, while average grain size α decreases 3.73 μm 1.96 μm, distribution varies compact scattering increases. Hf tends distribute β slower beneficial existence Hf. microhardness enhances monotonously, elongation ascends first, then high water-cooling attributed reduction volume fraction lath α’ martensite granular ω phase. fracture pattern ductile fracture, plasticity gets better with decreasing rate.