金属间化合物NiAl涂层的制备及耐腐蚀性能
Preparation and corrosion resistance properties of intermetallic NiAl coating
颜建辉 吴海江 唐思文
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作者单位:湖南科技大学先进材料制备及应用技术研究所
中文关键字:NiAl涂层; 等离子喷涂;抗氧化性; 耐腐蚀性
英文关键字:NiAl coating; plasma spraying; oxidation resistance; corrosion resistance
中文摘要:采用自蔓延高温合成方法制备了适合大气等离子喷涂用的NiAl粉末,在45钢基体上制备NiAl涂层,研究了涂层在800℃的高温氧化特性和室温下浸泡在4wt.%NaCl溶液中的耐腐蚀性能,利用XRD、SEM技术分析了涂层的高温氧化和耐腐蚀机理。结果表明,自蔓延高温合成方法制得的NiAl粉末主要由主相NiAl和少量Al3Ni相组成,制备的NiAl涂层致密且与基体结合良好。NiAl涂层在800℃氧化168h增重13.8mg.cm-2,约为45钢的1/10,提高了基体的高温抗氧化性能,归因于高温氧化过程中涂层表面变成了一层薄薄的Al2O3保护膜。45钢和NiAl涂层在4wt%NaCl溶液中浸泡腐蚀42d后失重分别为5.34mg.cm-2和1.23mg.cm-2,NiAl涂层具有较好的耐腐蚀性能。
英文摘要:NiAl powder was prepared by self-propagating high temperature synthesized technology. NiAl coating was successfully prepared on the 45 steel surface by air plasma spraying. The high temperature oxidation behaviors at 800℃ and corrosion resistance in 4%wt.NaCl solution at room temperature were studied. The oxidation and corrosion mechanism of coatings were also studied by XRD and SEM technology. The results indicate that the spraying powders were mainly composed of major NiAl phase and minor Al3Ni. The coating is dense and combined with substrate very well. The mass increase is 13.8 mg.cm-2 when NiAl coating was oxidized at 800℃ for 168h. The oxidation resistance of 45 steel was improved after coated with NiAl coating, which is contributed to a Al2O3 layer was formed on the NiAl coating. The mass loss of 45 steel and NiAl coating respectively are 5.34mg.cm-2 and 1.23mg.cm-2 when the samples were immersed in 4wt.%NaCl solution at room temperature. The NiAl coating exhibited fairly good corrosion resistance.