Heat Treatment Influencing Porosity and Tensile Properties of Field Assisted Sintered AlSi7Mg0.6

Abstract

In this study, an attempt was made to improve the mechanical properties and in particular the strength of a precipitation-hardenable aluminum alloy while still maintaining high ductility. For this purpose, AlSi7Mg0.6 (A357) powder with an average particle diameter of d50 = 40 µm was consolidated using field assisted sintering technique (FAST), and two material conditions were compared: an as-sintered and an underaging heat treated condition (T61). Mechanical properties were determined using tensile tests and hardness measurements. In addition, the microstructure was investigated by optical microscopy. Further, porosity and density were analyzed after the different heat treatments. By the underaging heat treatment, the surface hardness was increased by 100% and the yield strength was increased by 80% compared to the as-sintered material. However, the elongation to failure dropped to one third of that of the as-sintered material. Presumably, this effect was a result of an increased porosity due to the heat treatment. It is assumed that the observed pores were generated by artefacts from the FAST process used to manufacture the samples. The internal gas pressure and equilibrium diffusion supported by heat treatment temperature, and the reduction in surface energy caused by coalescent micropores, led to the enlargement of previously undetectable inhomogeneities in the as-sintered material that resulted in pores in the heat-treated sintered alloy.

Investigation of the Tribological Behaviour of Various AMC Surfaces against Brake Lining Material

“…It can be seen that the reinforcing particles have an angular shape. Furthermore, there are spherical eutectic Si particles in the aluminium matrix alloy (light grey colour in the micrograph), which are shaped by FAST process (see [ 20 ]).…”

Influence of Applied Load and Sliding Distance on Wear Performance of AlSi7Mg0.6 Aluminum Alloy

“…Most previous studies focus on the tensile [8][9][10][11] and fatigue properties [12][13][14][15] of AlSi7Mg0.6. Hirsch et al [8] indicated that the surface hardness and yield strength of A357 increased by 100% and 80%, respectively, for the materials With unique combinations such as high strength-to-weight ratio, excellent castability, supreme corrosion resistance and benign wear behavior, aluminum alloys are utilized in many scenarios. Casting aluminum alloys have obvious economic advantages over wrought aluminum alloys due to their shorter processing duration.…”

“…Most previous studies focus on the tensile [8][9][10][11] and fatigue properties [12][13][14][15] of AlSi7Mg0.6. Hirsch et al [8] indicated that the surface hardness and yield strength of A357 increased by 100% and 80%, respectively, for the materials of underaging heat treatment compared to the as-sintered material. Chen et al [9] proposed an empirical yield strength model to account for the effect of solidification and solution treatment.…”

Powder Metallurgy: Materials and Processing

“…The SI consists of 16 papers (published between 2022 and 2023): a review article [ 1 ], a viewpoint paper [ 2 ], a communication [ 3 ], and thirteen research articles [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. The papers reflect the current trends in the field: the search for new compositions (not investigated previously) of materials and the development of new processing approaches enabling better control and flexibility of the materials’ microstructures, shapes, and architectures.…”

“…The research papers report recent findings in metallic [ 4 , 5 , 6 , 7 , 8 , 9 ], ceramic [ 10 , 11 , 12 ], polymer [ 3 ], and composite materials [ 3 , 13 , 14 , 15 , 16 ].…”