Investigation of the effect of B₄C amount and sintering temperature on the thermal properties of the material in Al 1070–B₄C composites

Abstract

Today, the usage area of metal matrix and ceramic reinforced composites is increasing and researches in this field are increasing. However, majority of the studies conducted are constituted of studies on investigation of mechanical features of composites. One of the reasons why composite materials are preferred is because these materials have improved thermal property. With this experimental study, it is aimed to contribute to the literature in the area of investigating features of thermal properties. In this study, composite materials were produced at 500 °C, 550 °C and 600 °C sintering temperatures by adding 4%, 8% and 16% B4C to Al 1070 quality aluminium by powder metallurgy technique. Firstly, the microstructures of the composites were investigated. Then, experiments were conducted to determine the specific heat of composite materials at different ambient temperatures together with thermal conductivity measurements. With the data obtained from the experiments, finite-element modelling was done and the thermal properties of the composite structure were optimised. In the microstructure studies, it was determined that with the increase in the B4C reinforcement ratio, the reinforcement agglomeration and porosity in the composite structure were found. As a result of the thermal experiments, it was observed that the thermal conductivity values of the composites were inversely proportional to the amount of B4C reinforcement and as the reinforcement ratio increased, the thermal conductivity values decreased. Besides, it was determined that the sintering temperature has an effect on the thermal conductivity value and that it increases the thermal conductivity of the composites with increasing sintering temperature. The highest heat conduction coefficient was obtained at 4% B4C reinforcement ratio and 600 °C sintering temperature. It was observed that the finite-element models prepared to determine the heat conduction coefficient effectively were consistent with the experimental results.

Shot Peening Effect on Reduced Graphene Oxide-based AA1070 Alloys Produced by Stir Casting Technique

“…Due to the structural dissimilarity of graphene oxide in the aluminium matrix, there are difficulties in its homogeneous distribution in the matrix. For that reason, the studies on surface strengthening of graphene oxide added AMC have been carried out by using techniques such as stirred casting, liquid metal impregnation, sprayed deposition casting and so on (Toptan et al, 2010;Fadavi Boostani et al, 2018;Wu et al, 2019;Zheng et al, 2020a;Pehlivanlı & Pul, 2021). However, no study has been found on the graphene oxide-added AMCs with stirred casting so far using surface hardening processes like shot peening (Sun et al, 2018;Zhu et al, 2019;Rozhbiany & Jalal, 2019;Sasikumar et al, 2020) With the shot peening process, the surface of the graphene oxide structured AMC will be hardened by a massive amount of high hardness and high-speed kinetic energy projectiles (Zhu et al, 2016;Zhan et al, 2018a;Zhan et al, 2018b).…”