(1. 山東理工大學(xué) 機械工程學(xué)院，淄博 255000；
2. 山東大學(xué) 材料科學(xué)與工程學(xué)院，濟南 250061)
摘 要: 以AZ31鎂合金板材為實驗材料，先對其進行限制模壓變形，再利用超聲噴丸技術(shù)進行表面處理，研究限制模壓變形和超聲噴丸復(fù)合工藝對材料表層組織和硬度的影響。結(jié)果表明：限制模壓變形和超聲噴丸具有疊加效果，該復(fù)合工藝相對于單一工藝能進一步減小AZ31鎂合金的晶粒尺寸，增強表面硬度。經(jīng)復(fù)合工藝處理后，AZ31鎂合金的最小平均晶粒尺寸為7.52 μm，相比于原始試樣細化43.16%；表面硬度最高達到236 HV，相比于原始試樣提高306.90%。此外，與限制模壓變形相比，超聲噴丸對AZ31鎂合金表層組織和硬度的影響更加明顯。其中，隨著噴丸時間的增加，晶粒逐漸細化，硬度不斷升高，但當(dāng)處理時間達到400 s時，晶粒尺寸不再有明顯減小，硬度達到一定極限不再變化。
關(guān)鍵字: AZ31鎂合金；限制模壓變形；超聲噴丸；晶粒細化；硬度提高
（1. School of Mechanical Engineering, Shandong University of Technology, Zibo 255000, China;
2. School of Materials Science and Engineering, Shandong University, Jinan 250061, China）
Abstract:The effects of a composite process of constrained groove pressing (CGP) and ultrasonic shot peening (USP) on the surface microstructures and hardness of AZ31 magnesium alloy were studied. The results show that the superposition effect of CGP and USP can further reduce the grain size of AZ31 magnesium alloy and enhance the surface hardness compared with the single process. After the composite processing, the minimum average grain size of AZ31 magnesium alloy is 7.52 μm, which is 43.16% finer than that of the original sample, and the surface hardness is up to 236 HV, which is 306.90% higher than that of the original sample. In addition, the effect of USP on the surface microstructure and hardness of AZ31 magnesium alloy is more obvious than that of CGP. With the increase of USP treating time, the grains become finer and the hardness becomes higher continuously. However, when the treating time reaches 400 s, the grain size is no longer significantly reduced and the hardness reaches a certain limit.
Key words: AZ31 magnesium alloy; constrained groove pressing; ultrasonic shot peening; grain refinement; hardness increase
