A356 Alloy Research Articles

Mechanical Properties and Tribological Study of Bottom Pouring Stir-Cast A356 Alloy Reinforced with Graphite Solid Lubricant Extracted from Corn Stover

The present work epitomises extracting the graphite (Gr) solid lubricant from the corn stover. The extracted Gr was incorporated as reinforcement in the A356 alloy (Al-7Si), and the effect of the Gr particles on the mechanical and tribological properties was investigated. In spite of this, the input process parameters for the dry sliding wear test at room temperature against the EN31 steel disc were optimised through ANOVA analysis. The fabricated A359—X wt% (X = 0, 2.5, 5, 7.5) composite through bottom pouring stir casting techniques was analysed microstructurally by using XRD and FESEM analysis. The micro Brinell hardness and tensile strength were investigated per ASTME10 and ASTME8M standards. A wear test was performed for the composite pins against the EN31 steel disc according to ASTM G99 specifications. The XRD analysis results depict the presence of carbon (C), aluminium (Al), and silicon (Si) in all the wt% of the Gr reinforcement. However, along with the elements, the Al2Mg peak was confirmed for the A356—7.5 wt% Gr composite and the corresponding cluster element was confirmed in FESEM analysis. The maximum micro Brinell hardness of 92 BHN and U.T.S of 123 MPa and % elongation of 7.11 was attained at 5 wt% Gr reinforcement due to uniform Gr dispersion in the A356 alloy. Based on the ANOVA analysis, the optimal process parameters were obtained at 20 N applied load, 1 m/s sliding velocity, and 1000 m sliding distance for the optimal wear rate of 0.0052386 g/km and 0.364 COF.

Friction stir processing: A thermomechanical processing tool for high pressure die cast Al-alloys for vehicle light-weighting

This study uses friction stir processing (FSP) for thermomechanical processing of high-pressure die-casting (HPDC) to modify microstructure and improve mechanical properties. FSP is carried out on two different HPDC aluminum alloys: (a) general-purpose, high-iron, HPDC A380 alloy and (b) premium quality, low-iron HPDC Aural-5 alloy in thin wall, flat plate geometry. Subsequent mechanical testing shows ∼30 % and ∼65 % enhancement in yield strength and tensile ductility. In addition, FSP leads to ∼10 times improvement in fatigue life for A380 alloy and ∼70 % improvement in fracture toughness for Aural-5 alloy. These findings emphasize the capability of FSP to modify the microstructure of HPDC Al-alloys-based structural components so that they can demonstrate a good combination of strength, ductility, fracture toughness, and high fatigue properties for long-term durability and reliability.

Microstructural and mechanical Characterization of friction stir processed A356 alloy

Microstructural and mechanical Characterization of friction stir processed A356 alloy

Formation of seaweed morphology and enhancing mechanical properties of an A356 alloy by directional solidification

In the present work, regular dendrite and seaweed pattern are produced by controlling the crystal orientation during directional solidification of an A356 aluminium alloy. These morphologies and growth orientation were investigated by electron backscatter diffraction (EBSD), and the results showed that the seaweed pattern mainly prevailed under the (100)[011] orientation. At the same time, the effects of seaweed pattern in the properties of A356 alloy were analysed by room temperature tensile test. It was found that the elongation and toughness of the samples reached 20% and 36J/m3, respectively, for the seaweed; 13% and 24J/m3, respectively, for the regular dendrites; and 8% and 14J/m3, respectively, for the cast ingot. Compared with the regular dendrite samples, the seaweed pattern obtained relatively excellent elongation and toughness. By using scanning electron microscopy (SEM), it is found that the distribution of eutectic silicon particles in seaweed morphology sample is more refined and uniform, which is the main reason for these enhancements.

Effect of Fly Ash and Silica Particles on Mechanical and Thermal Properties of A-356 alloy

Arsalan, Feroz Shah, Quaid Jamal, Bilal Islam, Aizaz Ahmad Khan

Copper Slag as an Alternative to Silica Sand for A356 Alloy Casting-Feasibility Study

Copper Slag as an Alternative to Silica Sand for A356 Alloy Casting-Feasibility Study

Effect of Mn Addition on the Corrosion and Fatigue Properties of a Progressive Secondary A357 Alloy

Effect of Mn Addition on the Corrosion and Fatigue Properties of a Progressive Secondary A357 Alloy

3D morphological evolution of the Fe-Rich phase and mechanical properties of the recyclable A356 alloy

Efficient utilisation of recycled aluminium promotes low-carbon and green manufacturing in the aluminium industry. However, the low tolerance of Al for Fe content limits its application. The morphological evolution of the Fe-rich phase and the mechanical properties of recycled A356 alloys with varying Fe contents were investigated using optical microscopy (OM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), synchrotron radiation X-ray computed tomography (SRXCT), and Thermo-Calc thermodynamic calculations. The results show that with increasing Fe content, the morphology of the Fe-rich phase transformed from fine-granular and short rod-like structures into coarse needle-like and Chinese-script. In three dimensions (3D), the larger Fe-rich phases displayed a multibranched structure composed of rod-like and plate-like phases rather than a single morphology. Notably, at an Fe content of 0.4 %, the Fe-rich phases presented Chinese-script and short rod-like shapes in sections but did not significantly change the 3D morphology or type of the Fe-rich phase. However, the Fe-rich phases in the 0.4 %Fe alloy exhibited higher thickness and sphericity, which improved the ductility of the alloy. Thermodynamic calculations indicate that the initial formation temperature of the Fe-rich phase in the 0.4 % Fe alloy overlaps with that of the Al-Si eutectic reaction, which is referred to as the critical Fe content. At the critical Fe content, the ternary eutectic reaction of Al-Si-(AlFeSi) suppressed the rapid growth of the Fe-rich phase and mitigated their negative impact on ductility.

Microstructure evolution in A356 alloy subjected to controlled heat treatment regimes processes

Aluminium–silicon alloys are highly regarded for their lightweight and unique mechanical properties, making them crucial for various industrial applications. Achieving optimal mechanical behavior in Al-Si-based alloys necessitates meticulous control over their microstructure. The research investigated the impacts of heat treatment regimes on the microstructure of A356 hypoeutectic alloys by light optical microscope (OM), scanning electron microscope (SEM), and energy dispersive spectroscope (EDS). The alloy, produced via stir-casting, underwent homogenization at 540 °C/5 h, one-step (200 °C for 0.5–8 h (T1)) and two-step (T2 (200 °C/0.5 h/180 °C/0.5–8 h)), and T2L (200 °C/0.5 h/160 °C/0.5–8 h)) aging processes. The findings revealed significant microstructural changes due to heat treatment. Homogenization reduced the average grain size of eutectic silicon by 20.5%. The T1 treatment increased the grain size and changed the grain morphology with prolonged aging, negatively impacting the mechanical properties. The T2 and T2L treatments resulted in finer, more uniform grain structures. The T2L treatment produced the finest eutectic silicon and the most uniform grain distribution, indicating the superior potential for mechanical performance. Overall, this study underscores the importance of tailored heat treatment regimes to optimize the microstructure and enhance the structural sensitive properties of Al-Si alloys, benefiting automotive and aerospace industries.

Inhibiting Eutectic Si Macrosegregation in Squeeze Cast A356 Alloy by Symmetrical Multidirectional Pressure

The process of symmetrical multidirectional pressure was adopted to inhibit the macrosegregation of eutectic Si in squeeze cast A356 alloy. Five pressure modes were applied to study the effects of multidirectional pressure and the timing of pressure application on the macrosegregation of eutectic Si. The results show that the directional movement of the solute-rich liquid phase could be inhibited by symmetrical multidirectional pressure. Therefore, the macrosegregation of eutectic Si in the casting part was inhibited. Moreover, the timing of pressure application should be matched with the local pressure position. After the effective inhibition of the macrosegregation of eutectic Si, the elongation of the alloy was significantly improved, reaching up to 7.12%. In addition, the plastic deformation region was observed at the local pressure position. The grains in the plastic deformation region were refined. The proportion of low-angle grain boundaries in the deformed region was about 30%, which was much higher than that in the other undeformed region. The size of the Fe-containing intermetallics in the deformed region decreased to 5–10 μm, which is favorable for the mechanical properties of the alloy.

Numerical Simulation and Experimental Investigation of Microstructure Evolution and Flow Behavior in the Rheological Squeeze Casting Process of A356 Alloy

Numerical Simulation and Experimental Investigation of Microstructure Evolution and Flow Behavior in the Rheological Squeeze Casting Process of A356 Alloy

Hybrid Modification of Microstructure and Tensile Properties of A319 Alloy by Heat Treatment and Be Addition

Hybrid Modification of Microstructure and Tensile Properties of A319 Alloy by Heat Treatment and Be Addition

Influence of ultraviolet illumination on the corrosion behavior of 7A04 aluminum alloy in salt solutions with different pH values

This paper investigated the influence of ultraviolet (UV) illumination on the corrosion behavior of 7A04 aluminum alloy in 3.5% NaCl solutions with various pH values (pH=5.0, 7.0, and 10.0) using weight loss measurement, electrochemical methods, and surface analysis techniques. The research results indicated that the corrosion products of 7A04 alloy in salt solutions with different pH values all exhibited n-type semiconductor properties and could trigger the photovoltaic effect under UV illumination. Simultaneously, UV illumination reduced the compactness of the corrosion products, inhibited the enrichment of copper compounds (Cu2O), and promoted the generation of hydroxyl radicals in the solution. Therefore, UV illumination significantly accelerated the corrosion process of 7A04 alloy, with the overall acceleration effect ranking as follows: alkaline > neutral > acidic. In addition, the corrosion mechanism of 7A04 alloy in the test solutions with and without UV illumination was also discussed in this paper.

Experimental investigation of hybrid reinforced A356 aluminium alloy synthesised by stir casting technique

Abstract One of the most significant alloys to be employed in the automotive, aerospace, and military industries in recent years is A356 aluminium. Because of A356's excellent compatibility with other metals and nanoparticles, novel hybrid composites may be made using it. The characteristics of these hybrid composites are mostly the result of the additives' interaction with the A356 alloy's current elemental composition. Aluminium composites were synthesized through stir casting method by reinforcing 2%, and 4% SiC, 2% and 4 % Al2O3 and 0.5%, 1%, 1.5%, 2% and 2.5% SiC and Al2O3 both. The homogeneous distribution of SiC and Al2O3 microparticles in reinforced composite is revealed by scanning electron microscopy (SEM). The addition of SiC and Al2O3 reinforcements greatly improved the mechanical characteristics of the synthesised composites; for example, a composite with 4% SiC reinforcement reached its maximum hardness and maximum tensile strength of 165 HV and 257MPa respectively. Maximum elongation of 6.72 % was observed for 0.5% SiC and 0.5% Al2O3 reinforced composite. Minimum wear rate is observed for 4% SiC reinforced composite material. This study aims to identify gaps in the potential variations and compatibility of various additives with one another in order to create a brand-new hybrid reinforced alloy suitable for automotive braking system applications: brake rotors made of a disc or a brake pad, depending on the properties of the hybrid reinforced alloy that was made. Hence, the current work presented focuses on the preparation of hybrid reinforcement of A356 with silicon carbide and alumina powders.

Effect of process parameters on the mechanical properties of wires produced from A356 aluminum alloy chips by Continuous Friction Stir Extrusion: Experiments and numerical simulation

Recycling of metals is becoming crucial from an economic and environmental point of view. The solid-state recycling process Continuous Friction Stir Extrusion was used to produce wires out of A356-T6 chips. The mechanical properties of the produced wires were explored by varying the main process parameters. Characterization involved Vickers hardness tests, tensile tests, grain size measurements, and fracture surface analysis. It has been found that it is possible to achieve 77 % of the Ultimate Tensile Strength (UTS) and 92 % of Vickers hardness with respect to the as-fabricated A356 alloy. The average grain size increases with the tool rotational with values ranging from about 9 µm to about 11 µm. A 3D dedicated numerical model was used to predict the distributions and histories of primary field variables, and to calculate the Piwnik-Plata parameter, fostering a more in-depth understanding of the process mechanics. This allows for the precise prediction of unacceptable product quality of the bonding when the Plata and Piwnik parameters are low. Predicted temperature close to the rotating tool should reach 400 °C while the cochlea temperature should be below 100 °C for sound wires production thus avoiding early chip bonding and process failure.

Relationship between Microstructure and Wear Behaviour in A356 Alloy and A356/Al2O3 and A356/WC Composites After Casting and Hot-Extrusion

Relationship between Microstructure and Wear Behaviour in A356 Alloy and A356/Al2O3 and A356/WC Composites After Casting and Hot-Extrusion

Adaptive neuro-fuzzy inference system approach for tensile properties prediction of LPDC A357 aluminum alloy

This study is based on the desire of aluminum casting foundries to understand the influence of minor changes, within the specification limits, in the alloy chemistry. In order to ensure the casting of A357 Al alloys within the framework of the casting standards and to minimize the quality problems that may arise during casting; the estimation of ultimate tensile strength (UTS), yield strength (YS) and elongation (ε) due to very small changes among the alloying elements, although they are in the standard range, by using machine learning method (ML), were studied. The dataset of chemical composition and tensile properties of Low-Pressure Die Cast (LPDC) A357 Al alloy were experimentally established. The relationship between five input variables in the A357 alloy, namely the main alloying elements Si and Mg together with the most common impurity contents Fe, Ti and Cu were selected and three outputs (i.e UTS, YS and ε) were linked by Adaptive Neuro Fuzzy Inference System (ANFIS). The ANFIS model predicted that the most detrimental element affecting tensile properties was Fe content. According to this model, the order of the relative importance on UTS, YS and ε revealed as Si, Mg and Ti content respectively after the Fe content of the alloy.

Revealing the Relationship between Critical Inlet Velocity and a Double-Layer Oxide Film Combined with Low-Pressure Casting Technology

In the context of low-pressure casting, an excessive inlet velocity may result in the introduction of an oxide film and air into a liquid metal, leading to the formation of a two-layer film structure within the casting. Such defects can significantly degrade the mechanical properties of the castings. In order to optimize the advantages of low-pressure casting, an empirically designed equation for the inlet velocity was formulated and the concept of critical inlet velocity was further refined. A comprehensive numerical simulation was conducted to meticulously analyze the liquid metal spreading phase within the cavity. Subsequently, low-pressure casting experiments were carried out with actual castings of an A357 alloy, using two different entrance velocities—one critical and the other exceeding the critical entrance velocity. Tensile test specimens were extracted from the castings for the comparative evaluation of mechanical properties. It was observed that the average tensile strength of specimens cast at the critical inlet velocity exhibited a notable 16% enhancement. In contrast, specimens cast at velocities exceeding the critical inlet velocity manifested the presence of double oxide film defects. This evidence suggests that casting at a velocity faster than the critical inlet velocity leads to the formation of double oxide film defects, which in turn reduces the mechanical properties of the castings.

Superior tribological properties of highly-loaded graphite/A356 surface composites fabricated using friction stir processing

In this work, friction stir processing (FSP) was used to prepare graphite (Gr) / A356 alloy composites with superior tribological properties. The Gr content and number of FSP passes (up to three passes) were used as processing variables. The microstructure, hardness and wear resistance of the composites were studied and compared with a neat sample. The microstructural studies demonstrated that super-fine Gr particles were uniformly distributed and in-situ sub-micron Al4C3 particles were formed after three FSP passes. Hardness measurements proved that all composites exhibited higher hardness than the neat sample. The composite prepared using two Gr loading rounds and three FSP passes achieved the highest hardness value of 331 kg.f/mm2, which is more than 4 times that of the neat sample. Additionally, the wear rate of this composite was approximately 57 % lower than that of the neat sample. The superior hardness and wear resistance of the fabricated composites are attributed to the in-situ exfoliation of graphite and the formation of super-fine Al4C3 particles during FSP.

Impact of Melt Thermal Treatment and Artificial Aging on Microstructure and Mechanical Properties of A356 Alloy

Impact of Melt Thermal Treatment and Artificial Aging on Microstructure and Mechanical Properties of A356 Alloy