CeO2对铝合金表面激光增材制造组织及耐蚀性影响

Effect of CeO2 AdditionSon Interface Structure and Corrosion Resistance of Laser Additive Manufacturing on the Surface of Al Alloys

摘要:

利用激光增材制造技术,在6063Al基体表面制备了添加不同含量CeO₂的Ni60合金层,并通过金相显微镜、XRD、SEM和电化学腐蚀测试仪等设备进行了分析和测试,研究稀土CeO₂对6063Al表面激光增材制造镍基合金层与基体结合界面处的组织结构及耐腐蚀性能的影响。结果表明,在表面形貌上,4%~5% CeO₂的合金层形貌最好,CeO₂含量低于3%时难以获得表面良好的合金层,CeO₂含量在5%~10%时,合金层表面气孔、脱落等缺陷较少；在截面形貌上,合金层中CeO₂含量在0%~2%时易出现裂纹,含量在5%~10%时主要缺陷为气孔,4% CeO₂+Ni60合金层中无明显气孔和裂纹,具有相对较好的截面形貌；添加4% CeO₂可以改善Ni60合金层的组织结构,促进合金层的晶粒细化和组织分布均匀；添加不同含量CeO₂可以改善铝合金表面Ni60合金层的组织形貌,较佳的稀土添加量是4% CeO₂；在1mol/L H₂SO₄中,CeO₂ Ni60合金层的耐腐蚀性能是Ni60合金层的4.25倍；在3.5% NaCl溶液中,CeO₂ Ni60合金层耐腐蚀性能是Ni60合金层的1.4倍；在1mol/L NaOH溶液中,CeO₂ Ni60合金层的耐腐蚀性是Ni60合金层的1.43倍。

Abstract:

Ni60 alloy layers with different contends of rare-earth CeO₂ were prepared on the surface of 6063 aluminum alloy by using laser additive manufacturing. The effects of rare earth CeO₂ addition on microstructure, phase structure and corrosion resistance of bonding interface between Ni60-CeO₂ alloy layers and substrate were investigated by means of OM, XRD,SEM and electrochemical corrosion tester. The results show that on the surface morphology, 4%~5% CeO₂+Ni60 alloy layers have the best morphology, it is difficult to obtain a good alloy layer when the CeO₂ content of less than 3% . It is less surface pores, shedding and other defects when CeO₂ contents of 5% to 10% . On the cross-section morphology, the alloy layers prone to cracking at 0% to 2% CeO₂ content, the main defect is porosity when the content of 5% to 10%, 4% CeO₂ Ni60 alloy layer have no obvious pores and cracks, with a relatively good cross-section morphology. Adding 4% CeO₂ can improve the organizational structure of Ni60 alloy layer, promote grain refinement and compositions evenly distributed. Adding different contents of CeO₂ can improve aluminum surface morphology in Ni60 alloy layers, the preferred amount of rare earth CeO₂ is add 4% CeO₂. Electrochemical corrosion tests show that, the corrosion resistance of CeO₂ Ni60 alloy layer was 4.25 times as that of Ni60 alloy layer in 1mol/L H₂SO₄ solution. In 3.5% NaCl solution, the corrosion resistance of CeO₂ Ni60 alloy layer was 1.4 times as that of Ni60 alloy layer. In 1mol/L NaOH solution, the corrosion resistance of CeO₂ Ni60 alloy layer was 1.43 times as that of Ni60 alloy layer.