Effect of end chills, reinforcement content and carburization on the hardness of LM25-borosilicate glass particulate composite

Abstract

Aluminium metal matrix composites (AMCs) are widely employed in aerospace and automobile applications. Thus, they are required to operate reliably under a severe corrosive, high temperature and carbonaceous environments, without undergoing any deterioration in their mechanical properties. The paper is the compilation of the experimental results and analysis carried out to investigate the effect of different end chills, reinforcement content and carburization on the LM25 aluminium alloy reinforced with borosilicate glass powder. The composites are prepared via stir casting route by varying the weight percent (wt.%) of the reinforcement starting from 3 wt.% and going up till 12 wt.% with an increment of 3wt.% in every step. To obtain quality castings, end chills are placed within the sand mould. The specimens drawn from the chill-end of the castings are pack carburized in a muffle furnace for a set duration of time. The hardness of the specimens before and after carburization is recorded. The analysis of the results illustrates that the hardness increases linearly with the increase in the reinforcement content within the matrix from 3 wt.% up to 9 wt.%. It is also evident that the Volumetric Heat Capacities (VHC) of the chill material bears a strong effect not only on the quality of the castings produced but also on the hardness of the AMCs. Carburization leads to carbon deposition on the surface causing a change in the hardness of the specimens.

The dependency of the microhardnes on microstructure and solidification parameters of directionally solidified Al–4.5wt.%Cu in clay mold

“…These conditions are, on the one hand, promotes the increasing of λ1 and λ2; on the other hand, practically decreases the HV (Figure 5a). The similar result of the influence of the solidification parameters on improving the HV has reported by [7,[22][23][24][25][26]. High HV is at the minimum λ1 and λ2, and it gradually decreases as λ1 and λ2 increases.…”

An Investigation of the Thermal Properties of LM13- Quartz- Fly-Ash Hybrid Composites

“…Also AMCs exhibit improved resistance to corrosion and deformation, combined with excellent strength and elastic modulus [14,15]. AMCs reinforced with particles derived from oxides and carbides of ceramic materials such as SiC, Al 2 O 3 , B 4 C, SiO 2 , WC and MgO possess superior mechanical, thermal and electrical properties and were shown to perform better than their monolithic metallic counterparts in severe operating conditions requiring resistance to high temperatures and pressures [16][17][18][19]. Karthikraja et al reported that the inclusion of SiC and Al 2 O 3 particles within an aluminum alloy (Al 7075) matrix resulted in the production of stronger interfaces between the particles and the matrix alloy, which in turn reduced the rate of corrosion [20].…”

Wear Behavior and FESEM Analysis of LM 25 Alloy MMHCs Reinforced with FE3O4 and Gr by Utilizing Taguchi’s Technique

“…Hiremath investigated LM25-borosilicate glass particle composites using the stir casting method, and the findings show that the hardness improves linearly as the reinforcement amount inside the matrix increases. It is also clear that the cold material's Volumetric Heat Capacities have a significant impact not only on the quality of the castings produced but also on the hardness of the AMCs [24]. Elango et al [11] studied the wear properties of LM25 and composites supplemented with SiC and Titanium Dioxide (TiO2).…”