In situ formation of Al-Si-Mg based composite coating by different reactive thermal spray processes
In situ formation of Al-Si-Mg based composite coating by different reactive thermal spray processes
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DOI：
10.1016/j.surfcoat.2005.01.117
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发表时间：
2005-10
影响因子：
5.4
通讯作者：
I. Ozdemir;I. Hamanaka;M. Hirose;Y. Tsunekawa;M. Okumiya
中科院分区：
文献类型：
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作者：
I. Ozdemir;I. Hamanaka;M. Hirose;Y. Tsunekawa;M. Okumiya
与传统涂层相比，基于飞行过程中和撞击后的过程中反应的反应喷涂涂层提供了上级性能，因为它原位形成了细小且均匀分散的稳定硬质相。采用超音速火焰喷涂（HVOF）、射频等离子喷涂（RF）和直流等离子喷涂（DC）方法，在铝基体上制备了由镀镍层、SiO2微粒和Al-Si-Mg核心颗粒组成的复合粉末（SiO2/Ni/Al-Si-Mg）。在反应喷涂过程中形成的相的量和成分被发现是不同的，这取决于所使用的方法，其中过程中的反应不同地进行。结果表明，反应喷涂复合涂层主要由Mg 2Si、MgAl 2 O 4、NiAl 3和Al-Si基体组成，其中SiO2与Al-Si-Mg合金熔体发生放热反应。复合粉末中镁的耗尽是RF等离子喷涂复合涂层硬度较低的原因，RF等离子喷涂提供了最高的熔滴温度。
Reactively sprayed coatings based on in-process reactions during flight and after impingement offer superior properties compared with conventional coatings as it has in-situ formed fine and uniformly dispersed stable hard phases. In the present work, composite powder composed of plated nickel, fine SiO2particulates and Al-Si-Mg core particles with water glass binder (SiO2/Ni/Al-Si-Mg) was deposited onto an aluminum substrate to fabricate the composite coatings by using HVOF, RF and DC plasma spraying methods. The amount and constituents of the phases formed during reactive spraying were found to be different depending upon the methods used where in-process reactions differently proceed. Consequently, reactively sprayed composite coatings mainly consist of Mg2Si, MgAl2O4, NiAl3, and Al-Si matrix through the exothermic reaction of SiO2with molten Al-Si-Mg alloy. The depletion of magnesium in the composite powder is responsible for the obtained lower hardness of composite coatings sprayed by RF plasma spraying which offers the highest molten droplet temperature.