Al/Ni-WC复合涂层高温抗氧化性能与扩散分析  

High-temperature oxidation resistance and diffusion analysis of Al/Ni-WC composite coating

作　　者：李德元[1] 孙继博 李光全 张楠楠[1] 祝成 LI Deyuan;SUN Jibo;LI Guangquan;ZHANG Nannan;ZHU Cheng(School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,Liaoning,China;Chinese People′s Liberation Army Unit 32681,Tieling 112611,Liaoning,China)

机构地区：[1]沈阳工业大学材料科学与工程学院,辽宁沈阳110870 [2]中国人民解放军32681部队,辽宁铁岭112611

出　　处：《沈阳工业大学学报》2025年第2期197-204,共8页Journal of Shenyang University of Technology

基　　金：辽宁省自然科学基金项目(2022-MS-272);辽宁省“兴辽英才计划”项目(XLYC1807178)。

摘　　要：【目的】碳钢因其较差的抗氧化性能,在高温工况下的使用受到了严格限制。Ni-Al金属间化合物由于具有较高的熔点和较好的高温抗氧化性能,在实际工业领域应用众多。针对含有Ni-Al金属间化合物的涂层,研究其高温抗氧化涂层的进一步应用,提高碳钢的高温使用寿命,拟在碳钢表面制备Ni-Al反应改性涂层。【方法】采用超音速火焰喷涂在碳钢基体上制备Ni-WC涂层,随后在其上利用电弧喷涂制备Al涂层,在800℃不同时间扩散处理下使得涂层内的Ni-Al发生反应,以得到金属间化合物并增强其高温抗氧化性能。通过记录氧化增重曲线测试涂层的高温抗氧化性能。【结果】在高温氧化过程中Al/Ni-WC复合涂层在Al/Ni界面处原位生成了富铝的Ni-Al金属间化合物。Al/Ni-WC涂层经800℃扩散处理过程中,首先形成富Al的NiAl 3,且其表面Al原子与大气中的氧原子反应形成了Al_(2)O_(3)。随着反应时间的延长,在Al/Ni界面形成的NiAl 3相转变为抗高温氧化能力更优异的Ni_(2)Al_(3)相,两种Ni-Al金属间化合物本身具有高熔点和高温抗氧化性能,且在Al/Ni-WC复合涂层表面形成的Al_(2)O_(3)减缓了氧原子的扩散过程。Al/Ni-WC复合涂层试件的扩散层厚度随着扩散处理时间的延长呈现类似线性增长趋势。经800℃扩散处理后,Al/Ni-WC涂层中NiAl 3层的增厚速率较快,且在加热10 h后原位反应生成了更厚的Ni_(2)Al_(3)层。经800℃扩散处理20 h后,经过原位反应得到了比NiAl 3层稍厚一些的Ni_(2)Al_(3)层。由于Ni_(2)Al_(3)层熔点更高且更稳定,因而经过800℃扩散处理后的Al/Ni-WC涂层具有更好的高温抗氧化能力。经900℃/50 h扩散处理后的Al/Ni-WC涂层经循环氧化后存在陶瓷相Al_(2)O_(3)、WC和NiAl相,在陶瓷相和NiAl相的共同作用下呈现较好的高温抗氧化性能。测得不同扩散时间下Al/Ni-WC涂层的扩散层厚度,得到了Ni和Al之间的扩散关系式,�[Objective]The use of carbon steel in high-temperature working conditions is strictly limited due to its poor oxidation resistance.Ni-Al intermetallic compounds have many practical industrial applications due to their high melting points and good high-temperature oxidation resistance.In this study,a Ni-Al reaction-modified coating was prepared on the surface of carbon steel to explore the further application of coatings containing Ni-Al intermetallic compounds with high-temperature oxidation resistance and improve the high-temperature service life of carbon steel.[Methods]A Ni-WC coating was prepared on the carbon steel substrate by high-velocity oxygen-fuel(HVOF)spraying,and then an Al coating was prepared on it by arc spraying.The Ni-Al within the coating reacted under diffusion treatment for different time at 800℃to afford intermetallic compounds and thereby enhance high-temperature oxidation resistance.The high-temperature oxidation resistance of the coating was tested by recording their oxidation weight gain curves.[Results]The results show that the Al/Ni-WC composite coating generates Al-rich Ni-Al intermetallic compounds by in-situ reaction at the Al/Ni interface during high-temperature oxidation.The Al/Ni-WC coating forms Al-rich NiAl 3 during diffusion treatment at 800℃,and the Al atoms on the surface react with the atmospheric oxygen atoms to form Al_(2)O_(3).With the extension of the reaction time,the NiAl 3 phase formed at the Al/Ni interface is transformed into the Ni_(2)Al_(3) phase with better high-temperature oxidation resistance.The two Ni-Al intermetallic compounds have high melting points and high-temperature oxidation resistance,and Al_(2)O_(3) formed on the surface of Al/Ni-WC composite coatings slows down the diffusion of O atoms.The thickness of the diffusion layer of the Al/Ni-WC composite coating increases almost linearly with the prolongation of the diffusion treatment time.The thickness of the NiAl 3 layer of the Al/Ni-WC coating after the diffusion treatment at 800℃increases at a

关 键 词：电弧喷涂 超音速火焰喷涂 碳钢 原位生成 Al/Ni-WC复合涂层 Al/Ni界面 高温抗氧化性能 Ni-Al金属间化合物 

分 类 号：TG174.4[金属学及工艺—金属表面处理]