Corrosion and wear resistant WC17Co-TC4 composite coatings with fully dense microstructure enabled by in-situ forging of the large-sized WC17Co particles in cold spray
Corrosion and wear resistant WC17Co-TC4 composite coatings with fully dense microstructure enabled by in-situ forging of the large-sized WC17Co particles in cold spray
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DOI：
10.1016/j.jmatprotec.2021.117231
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发表时间：
2021-10
影响因子：
6.3
通讯作者：
Rui Cheng;Xiao-Tao Luo;Guosheng Huang;Chang-jiu Li
中科院分区：
文献类型：
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作者：
Rui Cheng;Xiao-Tao Luo;Guosheng Huang;Chang-jiu Li
虽然冷喷涂是一种潜在的替代，以产生高品质的钛基涂层，由于其低的工艺温度，冷喷涂钛或钛基合金通常表现出多孔的微观结构，因此不能提供有效的腐蚀保护的基板和表现较差的耐磨性。在这项工作中，一个额外的锻造/锤击效果的钛合金涂层引入大尺寸的WC 17 Co颗粒混合到TC 4粉末。在喷涂过程中，大尺寸WC 17 Co颗粒的冲击可以使沉积的TC 4颗粒塑性变形，从而原位致密化沉积的TC 4涂层。WC_（17）Co颗粒的嵌入有助于提高涂层的耐磨性。研究了原料粉末中WC 17 Co含量对涂层组织、腐蚀和磨损性能的影响。WC_（17）Co-TC_4复合涂层的孔隙率由16%降低到0.5%以下。复合涂层对基体具有良好的防腐蚀性能，80 vol. % WC 17 Co-TC 4复合镀层的耐蚀性最好。与纯TC 4涂层相比，涂层的腐蚀速率降低了100倍，在1000 h盐雾腐蚀试验后，涂层/基体界面没有腐蚀产物产生。随着原料中WC 17 Co含量的增加，耐磨性有提高的趋势。80vol. % WC 17 Co涂层的耐磨性比纯TC 4涂层高10倍。为冷喷涂制备钛及钛合金耐蚀耐磨涂层提供了一条新途径。
Although cold spray is a potential alternative to produce high quality Ti-based coatings due to its low process temperature, the cold sprayed Ti or Ti-based alloys usually exhibit a porous microstructure and thus cannot provide effective corrosion protection for the substrate and behave poor wear resistance. In this work, an additional forging/hammering effect for the Ti alloy coatings was introduced by mixing large-sized WC17Co particles into TC4 powder. During spraying, the impact of the large-sized WC17Co particles could plastically deform the deposited TC4 particles and therefore in-situ densify the deposited TC4 coating layer. The embedded WC17Co particles would help to improve the wear resistance of the coating. The effect of WC17Co content in the feedstock powder on microstructure, corrosion and wear performance of the coatings was examined. The porosity of WC17Co-TC4 composite coatings was reduced from 16 % to below 0.5 %. The composite coatings possessed excellent corrosion protection to substrates and the 80 vol.% WC17Co-TC4 composite coating showed the best corrosion resistance. As compared with the pure TC4 coating, the corrosion rate was reduced by 100 times and no corrosion production was observed at coating/substrate interface even after 1000 h salt-fog corrosion test. An increasing trend was detected in wear resistance with the proportion of WC17Co in the feedstock. The 80 vol.% WC17Co coating performed 10 times wear resistance higher than the pure TC4 coating. It is attempted to provide a new approach to develop corrosion and wear resistant Ti and Ti alloy coatings by cold spray.