Mechanical and Tribological Behavior of Ni(Al)-Reinforced Nanocomposite Plasma Spray Coatings
Mechanical and Tribological Behavior of Ni(Al)-Reinforced Nanocomposite Plasma Spray Coatings
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DOI：
10.1007/s11666-013-0041-6
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发表时间：
2014-02
影响因子：
3.1
通讯作者：
B. Movahedi
中科院分区：
文献类型：
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作者：
B. Movahedi
研究了Ni（Al）增强纳米复合等离子喷涂层的力学性能、摩擦学性能及组织演变。首先，将原料Ni（Al）-15 wt.%采用低能机械球磨法制备了纯Ni粉、纯Al粉以及Al 2 O3 - 13%TiO2纳米复合粉体。详细研究了粉末颗粒的特征和所制备的涂层取决于其微观结构。结果表明，球磨后的原料粉末中只有α-Ni固溶体，没有金属间化合物相。而在空气等离子喷涂条件下，α-Ni固溶体基体中出现了NiAl金属间化合物相。在低能量球磨过程中没有镍铝化物形成是有益的，因此，在等离子喷涂过程中Ni和Al之间可以发生放热反应，提高了纳米复合涂层的粘合强度。结果还表明，α-Ni相的显微硬度为3.91 ± 0.23GPa，NiAl金属间化合物相的平均显微硬度为5.69 ± 0.12GPa。纳米复合涂层的高显微硬度必须归因于增强纳米颗粒的存在。由于机械性能的改善，Ni（Al）纳米复合涂层在低摩擦系数下的耐磨性显示出显着的改进。
The mechanical and tribological behavior and microstructural evolutions of the Ni(Al)-reinforced nanocomposite plasma spray coatings were studied. At first, the feedstock Ni(Al)-15 wt.% (Al2O3-13% TiO2) nanocomposite powders were prepared using low-energy mechanical milling of the pure Ni and Al powders as well as Al2O3-13% TiO2nanoparticle mixtures. The characteristics of the powder particles and the prepared coatings depending on their microstructures were examined in detail. The results showed that the feedstock powders after milling contained only α-Ni solid solution with no trace of the intermetallic phase. However, under the air plasma spraying conditions, the NiAl intermetallic phase in the α-Ni solid solution matrix appeared. The lack of nickel aluminide formation during low-energy ball milling is beneficial hence, the exothermic reaction can occur between Ni and Al during plasma spraying, improving the adhesive strength of the nanocomposite coatings. The results also indicated that the microhardness of the α-Ni phase was 3.91 ± 0.23 GPa and the NiAl intermetallic phase had a mean microhardness of 5.69 ± 0.12 GPa. The high microhardness of the nanocomposite coatings must be due to the presence of the reinforcing nanoparticles. Due to the improvement in mechanical properties, the Ni(Al) nanocomposite coatings showed significant modifications in wear resistance with low frictional coefficient.