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采用超音速微粒轰击(SFPB)和表面机械滚压处理(SMRT)相结合的混合表面纳米化方法,在2A14铝合金上制备出梯度纳米结构(GNS)表层,对比研究了原始样品和常温空气及低温液氮环境下混合表面纳米化样品在3.5%Na Cl水溶液中的电化学腐蚀行为.结果表明:经混合表面纳米化处理后,2A14铝合金晶粒尺寸由最表层约30 nm逐渐增大到基体的原始尺寸,塑性变形层厚度约130 mm,表面粗糙度R_a约为0.6 mm,表面微小裂纹消失.与原始样品相比,经过SFPB处理的样品耐点蚀能力没有得到提高,混合表面纳米化样品的耐点蚀能力得到提高,其中常温空气环境下样品的自腐蚀电位和点蚀击破电位分别由-1.01228和-0.29666 V升高到-0.67445和0.026760 V,耐点蚀能力最强.分析表明,表层晶粒尺寸纳米化、晶界显著增多、残余压应力以及表面粗糙度的改善有利于提高样品的耐点蚀性能.
Gradient nanostructures (GNSs) were prepared on 2A14 aluminum alloy by hybrid surface nanostructuring (SFSB) combined with surface mechanical rolling (SMRT). The comparison between the original samples and normal temperature air and The results showed that the grain size of 2A14 aluminum alloy increased from about 30 nm in the outermost layer to The original size of the matrix, the plastic deformation layer thickness of about 130 mm, the surface roughness R_a of about 0.6 mm, the surface micro-cracks disappear.Compared with the original sample, the pitting resistance of the SFPB-treated samples did not improve, The pitting corrosion resistance of the samples was improved. The self-corrosion potential and pitting rupture potential of the samples increased from -1.01228 and -0.29666 V to -0.67445 and 0.026760 V, respectively, and their pitting corrosion resistance was the strongest. , The grain size of the surface is nano-sized, the grain boundaries are significantly increased, and the residual compressive stress and the improvement of the surface roughness are favorable for improving the pitting corrosion resistance of the sample.