Cold spray blended Al+Mg17Al12 coating for corrosion protection of AZ91D magnesium alloy
Cold spray blended Al+Mg17Al12 coating for corrosion protection of AZ91D magnesium alloy
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DOI：
10.1016/j.surfcoat.2012.06.050
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发表时间：
2012-08
影响因子：
5.4
通讯作者：
Hengyong Bu;M. Yandouzi;Chen Lu;D. MacDonald;B. Jodoin
中科院分区：
文献类型：
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作者：
Hengyong Bu;M. Yandouzi;Chen Lu;D. MacDonald;B. Jodoin
工业纯铝和掺有50 vol.%和75 vol.%采用冷喷涂工艺，在较低的工作气体压力和温度下，成功地在铸态AZ 91 D镁合金基体上沉积了50%的Mg 17 Al 12金属间化合物粉末。研究和讨论了添加和不添加增强颗粒的铝涂层的组织结构、力学性能和耐蚀性能。结果表明，在相同的沉积条件下，在纯铝原料中添加硬质颗粒可以显著降低涂层的孔隙率。虽然，只有一小部分（小于10 vol.%）涂层中保留了50%的Mg_（17）Al_（12）颗粒，涂层的硬度从47± 5 HV_（0.1）提高到58± 3 HV_（0.1），结合强度比纯Al涂层提高2 ~ 3倍。球形Mg 17 Al 12颗粒在金属基复合材料（MMC）涂层中起到类似于硬质陶瓷增强颗粒的作用。电化学腐蚀实验也表明，复合涂层具有类似的块体铝的电化学特性，他们可以提供适当的保护铸态AZ 91 D镁材料。
Commercially pure aluminum and aluminum blended with 50vol.% and 75vol.% of the intermetallic Mg17Al12compound feedstock powders were successfully deposited onto as cast AZ91D magnesium substrate using a cold spray process that was employed at low working gas pressure and temperature. The microstructure, mechanical performance and corrosion resistance properties of the Al coatings with and without reinforcement particles were investigated and discussed. The results show that under the same deposition conditions, the coating porosity level can be significantly decreased by adding hard particles into the pure aluminum feedstock. Although, only a small fraction (less than 10vol.%) of the Mg17Al12particles was retained in the coatings, the hardness, was increased from 47±5HV0.1to 58±3HV0.1, while the bonding strength was 2 to 3 times higher than the pure Al coating. The spherical Mg17Al12particles play a role similar to that of the hard ceramic reinforcement particles in the metal matrix composite (MMC) coatings. Electrochemical corrosion experiments also demonstrated that the composite coatings have similar electrochemical characteristics to the bulk Al, and they can provide suitable protection for the as cast AZ91D magnesium material.