摘要
To enhance the mechanical properties and corrosion resistance of magnesium alloys,high-energy shot peening(HESP)was used.According to the results,the in-situ surface nanocrystallization(ISNC)microstructure was fabricated on the magnesium alloy surface,and its formation mechanism was the coordination among twins,dislocations,subgrain boundary formation and dynamic recrystallization.Under the released surface stress of sample,the residual compressive stress and microhardness rose,thus enhancing compactness of the surface passivation film Mg(OH)2.Besides,the corrosion rate dropped by 29.2% in maximum.In the polarization curve,the maximum positive shift of the corrosion potential of sample was 203 mV, and the corrosion current density decreased by 31.25% in maximum.Moreover,the compression resistance and bending resistance of the bone plate were enhanced,and the maximum improvement rates were 18.2% and 23.1%,respectively.Accordingly,HESP significantly enhanced mechanical properties and corrosion resistance of magnesium alloys.
为提高镁合金的力学性能和耐腐蚀性能,采用高能喷丸技术(HESP)对其进行强化。结果表明,在镁合金表面制备原位表面纳米结晶(ISNC)显微组织,其形成机制是通过孪晶、位错、亚晶界形成和动态再结晶相互协调作用实现的。在样品表面释放应力的作用下,残余压应力和显微硬度增加,从而增加表面钝化膜Mg(OH)2的致密性。此外,腐蚀速率最大降低了29.2%。在极化曲线中,样品的腐蚀电位最大正向偏移量为203 mV,腐蚀电流密度最大下降了31.25%。另外,骨板的抗压性能和抗弯性能得到改善,最大增加率分别达到18.2%和23.1%。因此,HESP显著改善了镁合金的力学性能和耐腐蚀性能。
基金
Project(51872122) supported by the National Natural Science Foundation of China
Projects(2017GGX30140,2016JMRH0218) supported by the Key Research and Development Plan of Shandong Province,China
Project(2016-2020) supported by Taishan Scholar Engineering Special Funding of Shandong Province,China
