Evaluating the Tensile Properties of Aluminum Foundry Alloys through Reference Castings—A Review

Proceedings of the Institution of Mechanical Engineers, Part L:

2019

In the current scenario, the light-weighting concept is the most important strategy to decrease fuel consumption as well as emissions of greenhouse gases. Magnesium alloys are attractive to various industries including transportation industry for their inherent light-weight. The friction stir welding is proficient to join magnesium alloys. In this article, a dissimilar friction stir welding butt joint between AZ31 and AZ61 magnesium alloys was fabricated, and microstructure and mechanical properties have been examined. The tool rotation speed of 1400 r/min and tool transverse feed rate of 25 mm/min was found quite suitable to fabricate a perfect joint of these dissimilar magnesium alloys. The stir zone was composed of fine and equiaxed grains and showed the highest microhardness value. In the advancing side, heat affected zone was composed of both equiaxed and elongated grains; however, in the retreating side, heat affected zone has relatively smooth grains. The tensile strength of the joint was about 138.37 ± 6.6 MPa. The efficiency of the joint was 51.25% with respect to AZ61 Mg alloy. The average impact toughness of friction stir welding joint was deteriorated by 16.67% and 28.5% with respect to base materials AZ31 and AZ61, respectively.

Section: Methodsmentioning

confidence: 99%

Investigation on the microstructure and mechanical properties of a dissimilar friction stir welded joint of magnesium alloys

Proceedings of the Institution of Mechanical Engineers, Part L:

2019

“…The results in Table 4 show that the strength, ductility and hardness of the cast bars all increased as section size decreased or as cooling rate increased. The tensile properties (tensile strength and ductility) are particularly so well correlated [28] [29]. The ratio of strength to ductility approximates to a constant value of 16.…”

Section: Relationships Between Mechanical Propertiesmentioning

confidence: 85%

Effect of Section Size as a Measure of Cooling Rate on the Solidified Microstructure and Mechanical Properties of Sand-Cast Al-Si Eutectic Alloy

Mark

2020

IJET

Several factors contribute to the development of structure and properties of aluminiumalloy castings. This study investigated the singular effect of cooling rate on the as-cast structure andmechanical properties of an aluminum-silicon eutectic alloy, keeping other factors such as pouringtemperature, melt treatments, physical and thermal properties of the mould, and alloy compositionconstant. The rate of cooling was varied by employing different casting section sizes, based on thevariation of rate of heat extraction given by solidification time as predicted by the Chvorinov’s rule.Four test bars of section sizes 10, 20, 30, and 40 mm respectively were cast in sand mould using thesame gating system. Spectrometric analysis of the alloy formulated revealed that it could be specifiedapproximately as Al-12.8Si-1.0Cu alloy. The study showed that as section size decreased from 40mm to 10 mm; the solidification time reduced (i.e. the cooling rate increased), the microstructure gotfiner, the silicon flakes became more uniformly distributed, and the mechanical properties generallyimproved. The tensile strength, ductility, and hardness all increased in the order of decreasing sectionsize, i.e. increasing cooling rate. The mechanical properties were found to be linearly correlated withsection size or cooling rate. Whereas the elongations were lower than values for pure aluminium, thestrength and hardness were significantly higher than values for the pure metal. It is concluded thatthe cooling rate modifies the microstructure and improves the mechanical properties of as-cast Al–Sieutectic alloys

“…Similar findings have been reported by Anilchandra. 47 After post welding heat treatment, the grain structure of stir zone was marginally improved and grains were recrystallized. Heat cycle softened material and grain size further became more homogeneous.…”

Section: Microstructurementioning

confidence: 99%

Influence of post welding heat treatment on the microstructure and mechanical properties of friction stir welding joint of AZ31 Mg alloy

Singh²,

Proceedings of the Institution of Mechanical Engineers, Part E:

2021

At present, magnesium alloys are extensively used in numerous applications due to their light weight and better characteristics. Welding of magnesium alloys is regarded as one of the most complex phenomena in various industries. The friction stir welding of magnesium alloys has encouraged abundant scientific and industrial interest as it has the potency to form a good quality joint. Post welding heat treatment is an appropriate process to further improve the properties or performance of FSW joints. Therefore, the present work aims to join AZ31 Mg alloy plates by friction stir welding, and microstructural and mechanical properties of the joint have been examined. Furthermore, the consequence of post welding heat treatment on the microstructure and mechanical properties of FSW joint has been evaluated. Tensile strength and elongation of FSW joint were about 145.4 ± 4.9 MPa and 9.5 ± 0.9%, respectively. It was found that post welding heat treatment was beneficial in homogenizing grains and to enhance mechanical properties. Tensile strength and elongation of the joint were improved by 4.74% and 15.78% respectively after PWHT. The highest microhardness of stir zone decreased about 6.84% (73 Hv to 68 Hv) after heat treatment and hardness pattern of weld became relatively smooth. Toughness of PWHT joint was 4.5 ± 0.17 Joules. The mode of tensile failure of as-welded and PWHT joint was ductile.