Abstract

The microwave processing of materials is considered as a novel and sustainable process due to the unique heating properties, huge saving of energy and processing time and non-polluting characteristics. The purpose of the present work is to economically process nickel powder-based metal matrix composites reinforced with variable (5% and 10%) volume fraction of alumina powder through microwaves at 2.45 GHz frequency and 900-W power. The concept of microwave hybrid heating is used for heating and melting the nickel-based powders. Developed composites were characterized through phase analysis, microstructural characterizations, mechanical characterizations and wear study. The XRD analysis of alumina-reinforced composites revealed the formation of nickel aluminides (AlNi and NiAl₃), intermetallic of nickel such as Ni₃Si and FeNi₃, oxides of nickel and chromium carbides (Cr₃C₂, Cr₂₃C₆ and Cr₂C₃). Microstructures revealed formation of equiaxed grains with uniform dispersion of alumina reinforcements. The microhardness of composites was increased due to the presence of uniformly distributed alumina reinforcements and presence of intermetallics. Vickers microhardness for 10% alumina-reinforced MMC was 2.4 times higher than pure EWAC casting. The 10% ceramic reinforcement increased the tensile strength and wear resistance. For 10% alumina composite, wear was reduced by 71.67% in comparison with pure nickel-based casting.

Graphic Abstract

中文翻译：

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通过微波加热工艺原位制备镍铝金属粉末基复合材料：一种可持续的方法

摘要

材料的微波处理由于其独特的加热特性，巨大的能源和处理时间节省以及无污染的特性而被认为是一种新颖且可持续的工艺。本工作的目的是通过微波以2.45 GHz频率和900 W功率经济地处理体积可变（5％和10％）的氧化铝粉增强的镍粉基金属基复合材料。微波混合加热的概念用于加热和熔化镍基粉末。通过相分析，微结构表征，机械表征和磨损研究对复合材料进行表征。氧化铝增强复合材料的XRD分析表明形成了铝化镍（AlNi和NiAl ₃），镍的金属间化合物（如Ni ₃ Si和FeNi _3），镍和碳化铬的氧化物（Cr ₃ C ₂，Cr ₂₃ C ₆和Cr ₂ C ₃）。微观结构表明，等轴晶粒形成了氧化铝增强材料均匀分散的状态。由于存在均匀分布的氧化铝增强材料和金属间化合物，复合材料的显微硬度得以提高。10％氧化铝增强的MMC的维氏显微硬度比纯EWAC铸件高2.4倍。10％的陶瓷增强材料提高了拉伸强度和耐磨性。与纯镍基铸件相比，对于10％的氧化铝复合材料，磨损降低了71.67％。

图形摘要