Effect of Al-5Ti-1B Grain Refiner on Microstructure and Hardness of V-Al Alloys for Hydrogen Separation

5wt% Al and 5wt% A1-5Ti-IB (ATB) master alloy (grain refiner) were added into pure V to form V-5A1 and V-5ATB alloy ingots by arc melting. Optical microscope (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and microhardness tester were used to analyze the microstructure and hardness variation of V-Al alloy before and after grain refinement. The results show that the grain size of V-5ATB alloy decreases obviously due to the precipitation of long needle -like second phases TiB. Compared with V-5A1 alloy, the hardness of V-5ATB alloy increases due to strengthening effect of solid solution, fine grain and hard TiB phase.