Nagaraja Santhosh, Nagegowda Kempaiah Ujjaini, Kumar V Anand, Alamri Sagr, Afzal Asif, Thakur Deepak, Kaladgi Abdul Razak, Panchal Satyam, Saleel C Ahamed
Department of Mechanical Engineering, MVJ College of Engineering, Bengaluru 560067, India.
Department of Mechanical Engineering, University Visvesvaraya College of Engineering, Bangalore University, Bengaluru 560001, India.
Materials (Basel). 2021 May 9;14(9):2452. doi: 10.3390/ma14092452.
The choice of suitable inoculants in the grain refinement process and subsequent enhancement of the characteristics of the composites developed is an important materials research topic, having wide scope. In this regard, the present work is aimed at finding the appropriate composition and size of fly ash as inoculants for grain refinement of the aluminum AA 5083 composites. Fly ash particles, which are by products of the combustion process in thermal power plants, contributing to the large-scale pollution and landfills can be effectively utilized as inoculants and interatomic lubricants in the composite matrix-reinforcement subspaces synthesized in the inert atmosphere using ultrasonic assisted stir casting setup. Thus, the work involves the study of the influence of percentage and size of the fly ash dispersions on the tensile and impact strength characteristics of the aluminum AA 5083/7.5SiC composites. The C type of fly ash with the particle size in the series of 40-75 µm, 76-100 µm, and 101-125 µm and weight % in the series of 0.5, 1, 1.5, 2, and 2.5 are selected for the work. The influence of fly ash as distinct material inoculants for the grain refinement has worked out well with the increase in the ultimate tensile strength, yield strength, and impact strength of the composites, with the fly ash as material inoculants up to 2 wt. % beyond which the tensile and impact characteristics decrease due to the micro coring and segregation. This is evident from the microstructural observations for the composite specimens. Moreover, the role of fly ash as material inoculants is distinctly identified with the X-Ray Diffraction (XRD) for the phase and grain growth epitaxy and the Energy Dispersive Spectroscopy (EDS) for analyzing the characteristic X-Rays of the fly ash particles as inoculant agents in the energy spectrum.
在晶粒细化过程中选择合适的孕育剂以及随后改善所开发复合材料的特性是一个重要的材料研究课题，具有广泛的研究范围。在这方面，目前的工作旨在找到合适的粉煤灰成分和尺寸，作为AA 5083铝合金复合材料晶粒细化的孕育剂。粉煤灰颗粒是火力发电厂燃烧过程的副产品，会造成大规模污染并占用填埋场空间，可在惰性气氛中使用超声辅助搅拌铸造装置合成的复合基体-增强子空间中有效地用作孕育剂和原子间润滑剂。因此，这项工作涉及研究粉煤灰分散体的百分比和尺寸对AA 5083/7.5SiC铝合金复合材料拉伸强度和冲击强度特性的影响。选择粒径在40-75 µm、76-100 µm和101-125 µm系列，重量百分比在0.5、1、1.5、2和2.5系列的C型粉煤灰用于这项工作。随着复合材料极限抗拉强度、屈服强度和冲击强度的增加，粉煤灰作为独特的材料孕育剂对晶粒细化的影响效果良好，粉煤灰作为材料孕育剂的含量高达2 wt.%，超过此含量后，由于微缩孔和偏析，拉伸和冲击特性会下降。这从复合材料试样的微观结构观察中可以明显看出。此外，通过X射线衍射（XRD）分析相和晶粒生长外延，以及通过能谱分析（EDS）分析粉煤灰颗粒作为孕育剂在能谱中的特征X射线，明确确定了粉煤灰作为材料孕育剂的作用。
