研究了铸态ZK60镁合金粉末的氢化-脱氢优化技术及其在此过程中的晶粒尺寸纳米化机理。通过XRD、OM和TEM考察了氢化-脱氢过程中ZK60镁合金粉末相结构和显微组织演化规律,获得了制备纳米晶材料的氢化、脱氢工艺条件。结果表明:ZK60合金粉末在450℃、2 MPa条件下保温12 h后能够完全氢化,随后在350℃保温并连续抽真空3 h即可完全脱氢,在此过程中ZK60合金粉末的平均晶粒尺寸也从约150μm被细化到约30 nm。
A hydrogenation-desorption technique was applied to process as-cast ZK60 alloy, and the nanocrystallization mechanism in this process was studied. The phase and microstructure evolution of ZK60 alloy powders at different states(before hydrogenation, after hydrogenation and after desorption) were characterized by powder X-ray diffraction, optical microscopy and transmission electron microscopy. The results reveal that ZK60 powders are completely hydrogenated at 450 ℃ under 2 MPa for 12 h and then thoroughly dehydrogenated at 350 ℃ for 3 h in vacuum; meanwhile, the grain sizes of ZK60 alloy powders are refined from 150 μm to 30 nm.