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纳米晶体材料优异的力学性能和特殊的变形机制为其工程应用奠定了基础。为探究纳晶材料的力学性能与变形机制,以高致密度和高纯度纳晶镍片为研究对象,利用微划痕技术测试其划痕硬度、抗划痕性能、划痕回弹性能、摩擦力与摩擦系数等力学行为,并与粗晶镍片进行了对比。结果表明,纳晶试样具有较高的划痕硬度和抗划痕能力以及较低的摩擦力与摩擦系数。同时,基于划痕力学行为探讨了2种试样的塑性变形机制。结果显示,纳晶镍试样的塑性变形机制以晶界滑移和晶间扩散为主,而粗晶镍试样的塑性变形中位错的发射与堆积占主导。
The excellent mechanical properties and special deformation mechanisms of nanocrystalline materials lay the foundation for their engineering application. In order to investigate the mechanical properties and deformation mechanism of nanocrystalline materials, the high-density and high-purity nanocrystalline nickel sheets were used as the research objects. The scratch resistance, scratch resistance, scratch resilience, friction Force and friction coefficient and other mechanical behavior, and compared with coarse grain nickel. The results show that the nanocrystalline samples have higher scratch hardness and scratch resistance as well as lower friction and friction coefficient. At the same time, the plastic deformation mechanism of two kinds of samples was discussed based on the scratch behavior. The results show that the plastic deformation mechanism of nanocrystalline nickel samples is dominated by grain boundary slip and intergranular diffusion, while the emission and deposition of dislocations dominated the plastic deformation of coarse-grained nickel specimens.