Preparation of MCrAlY-Al2O3 Composite Coatings with Enhanced Oxidation Resistance through a Novel Powder Manufacturing Process
Preparation of MCrAlY-Al2O3 Composite Coatings with Enhanced Oxidation Resistance through a Novel Powder Manufacturing Process
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DOI：
10.1007/s11666-019-00830-y
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发表时间：
2019-02-01
影响因子：
3.1
通讯作者：
Hussain, Tanvir
中科院分区：
文献类型：
--
作者：
Bai, Mingwen;Song, Bo;Hussain, Tanvir
以自制的复合粉末为原料，采用高速氧燃料热喷涂技术制备了高温用MCrAlY-Al_2O_3复合涂层。采用悬浮法制备了-Al_2O_3亚微米颗粒在MCrAlY粉末表面的细小分散。然而，由于喷雾过程中原料的流动性降低了50%，这一点受到了影响。然而，本研究中介绍的新型粉末制造工艺已显示出作为制备定制复合材料粉末原料用于生产金属基复合材料的潜在的替代途径。此外，与传统的MCrAlY涂层相比，新开发的MCrAlY-Al_2O_3复合涂层具有更好的抗氧化性，在900℃恒温氧化10h后，几乎完全形成了Al_2O_3膜。在MCrAlY涂层中添加-Al_2O_3颗粒作为第二相，促进了喷涂过程中YxAlyOz氧化物的生成，并加速了Al的向外扩散，从而提高了涂层的抗氧化性。
MCrAlY-Al2O3 composite coatings were prepared by high-velocity oxygen fuel thermal spraying with bespoke composite powder feedstock for high-temperature applications. Powder processing via a suspension route was employed to achieve a fine dispersion of -Al2O3 submicron particles on the MCrAlY powder surface. This was, however, compromised by 50% less flowability of the feedstock during spraying. Nevertheless, the novel powder manufacturing process introduced in this study has shown potential as an alternative route to prepare tailored composite powder feedstock for the production of metal matrix composites. In addition, the newly developed MCrAlY-Al2O3 composite coatings exhibited superior oxidation resistance, compared to conventional MCrAlY coatings, with the formation of nearly exclusively Al2O3 scale after isothermal oxidation at 900 degrees C for 10h. The addition of -Al2O3 particles in the MCrAlY coatings as a second phase was found to have promoted the formation of YAG oxides (YxAlyOz) during spraying and also accelerated the outwards diffusion of Al, which resulted in enhanced oxidation resistance.