Cast Aluminum Alloy Research Articles

An investigation of process parameter influences on dissimilar friction stir welding of cast aluminum alloy joints

ABSTRACTCast alloys find suitable employability in industrial applications favoring automotive and aerospace sectors owing to their high specific strength, low porosity, excellent fluidity, and machinability. The present study focuses on friction stir welding of cast aluminum alloys (AA356 and AA2014) with a varied range of process parameters, namely, tool pin shape (cylinder, cone, square, and threaded cylinder), tool speed (1800–2100 rpm), and tool feed (5–20 mm min−1). The novelty of the present work spotlights/features the implementation of L16 orthogonal design with the analysis of variance, grey relational analysis, fuzzy logic system, and artificial neural network approaches to contemplate the weld quality of cast joints. The microstructural analysis and grain size estimation is comprehended in the study. Regression models have been developed based on the analysis of variance. The prime factors favoring the ultimate tensile strength and microhardness were 2100 rpm, 10 mm min−1, and threaded cylinder shape. The findings from the analysis of variance and grey relational analysis are in concurrence with each other. The results of fuzzy logic showcased a substantial improvement in terms of grey relational grade. The results from the artificial neural network deliver rational evidence for the analysis of variance conducted on the selected tool pin shapes.

Joining of Aluminum and CFRP via Laser Powder Bed Fusion: Influence of Experimental Set-Up and Laser Processing on Microstructure and Mechanical Properties.

Additive-manufacturing-based joining methods enable tailored or even functionalized joints and allow for hybridization at small scales. The current study explored an innovative joining method for aluminum cast alloys (AlSi12) with thermoset carbon-fiber-reinforced polymers (CFRPs) via laser powder bed fusion (LPBF). The direct build-up of AlSi12 on a CFRP substrate proved to be challenging due to the dissimilar thermal properties of the considered materials, which led to substrate damage and low joint adhesion. These effects could be overcome by introducing an AlSi12 foil as an interlayer between the two joining partners, acting as a thermal barrier and further improving the AlSi12 melt wettability of the substrate. Within LPBF, the energy input in the form of volumetric laser energy density influenced both the porosity of the fused layers and the formation of thermally induced stresses due to the high cooling rates and different thermal expansion properties of the materials. While the AlSi12 volume density increased with a higher laser energy input, simultaneously increasing thermal stresses caused the debonding and deformation of the AlSi12 foil. However, within a narrow processing window of laser parameters, the samples achieved remarkably high shear strengths of τ > 20 MPa, comparable to those of conventional joining methods.

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

The wear performance of AlSi7Mg0.6 aluminum alloy, a casting aluminum alloy used in positioning devices for catenary systems of high-speed railways which fail frequently on lines where the speed of trains is higher than 300 m/s, is discussed in this study. It was estimated that sliding contact wear occurred and mainly contributed to the failure. To explore the competing mechanism for frictional wear failure, frictional experiments based on three groups of sliding distance (0.5 mm, 1.5 mm and 3.0 mm) and four groups of applied loads (20 N, 50 N, 100 N and 200 N) were implemented. Three-dimensional morphological observation results revealed that the wear volumes at a sliding distance of 0.5 mm were only about 1/10 of that at a sliding distance of 3.0 mm. It was also revealed that the wear volume based on a sliding distance of 3.0 mm and applied load of 20 N was still much larger than the wear volume under a sliding distance of 0.5 mm and applied load of 200 N. SEM observation of the microstructures revealed that abrasive wear was the dominant wear mechanism in dry sliding friction conditions. A simplified positioning device model was also established to study the influence of tension force on wear performance. The simulation results revealed that smaller tension force between the positioning support and positioning hook would lead to higher relative sliding distance and larger wear depth. Sliding contact friction should be avoided due to relatively large wear efficiency compared with rolling contact friction. Both experimental and simulation results suggested that proper tension force was preferred in assembling components which could ensure rolling contact friction rather than sliding contact friction.

Effect of spherical crown texturing and ionized sulfur infiltration on the tribological performance of piston-cylinder liner

In this study, the piston-cylinder liner was treated with single glow photoionization sulfurization of a cast aluminum alloy (AlSi10Mg), and the effect of the spherical crown texture on frictional properties of the piston-cylinder liner were investigated before and after the sulfurization treatment. The treated specimens were characterized and evaluated via microscopic morphological analysis, three-dimensional morphological analysis, X-ray diffraction (XRD), thin film diffraction, microhardness testing, and friction wear experiments. Fluent fluid analysis software was used to develop a flow field simulation model for the spherical crown texture. Results of the study showed that the average friction coefficients of the specimens treated with sulfur infiltration were all lower than those of untreated specimens, and the low friction coefficients were closely related to the laminar structure and weak interfacial bonding of the sulfur infiltration layer. The spherical crown structure effectively affected the stree distribution on surface of the specimens uniformly, which improved the bearing capacity and durability of the specimens, and the surface texture helped reduce the contact area and store the debris generated during the wear process, thus improving the friction performance. Mechanical stamping caused material aggregation on the edges of the weave, which increased the hardness of the edges and thus reduces the increase in wear around the weave. The surface microstructure of the specimens was effectively improved after sulfurization treatment, leading to higher wear resistance for the sulfurized specimens. Given the relative lack of research on the composite ionic sulfurization of piston-cylinder liner spherical crown texture at home and abroad, this experiment provides data support for this direction. The results provide beneficial clues for the design and optimization of the piston-cylinder liner spherical crown structure.

Thermomechanical Joining of Hypoeutectic Aluminium Cast Plates

Consistent lightweight construction in the area of vehicle manufacturing requires the increased use of multi-material combinations. This, in turn, requires an adaptation of standard joining techniques. In multi-material combinations, the importance of integral cast components, in particular, is increasing and poses additional technical challenges for the industry. One approach to solve these challenges is adaptable joining elements manufactured by a thermomechanical forming process. By applying an incremental and thermomechanical joining process, it is possible to react immediately and adapt the joining process inline to reduce the number of different joining elements. In the investigation described in this publication, cast plates made of the cast aluminium alloy EN AC-AlSi9 serve as joining partners, which are processed by sand casting. The joining process of hypoeutectic AlSi alloys is challenging as their brittle character leads to cracks in the joint during conventional mechanical joining. To solve this, the frictional heat of the novel joining process applied can provide a finer microstructure in the hypoeutectic AlSi9 cast alloy. In detail, its Si is finer-grained, resulting in higher ductility of the joint. This study reveals the thermomechanical joining suitability of a hypoeutectic cast aluminium alloy in combination with adaptively manufactured auxiliary joining elements.

Possibility of Using Unshaped Thermal Insulation of Aluminum Alloy Castings

Possibility of Using Unshaped Thermal Insulation of Aluminum Alloy Castings

Study on Failure Mode of Cast Aluminum Alloy in Marine Environment

Aluminum alloy is an important metal material in the industrial field. With good mechanical properties, the ZL205A high-strength casting aluminum alloy has been widely used in aviation, aerospace, and other fields. In this paper, the erosion phenomenon of the ZL205A cast aluminum alloy on a certain type of marine equipment is described, and the failure mode of the ZL205A cast aluminum alloy in the marine environment is analyzed by simulation calculation and experimental verification. It provides technical support for the antierosion treatment and structural optimization of subsequent casting aluminum alloy equipment.

Microstructural and mechanical characteristics of AlSi5Cu3 aluminum alloy cast in metal mold and sand mold

In this effort, the impact of mold material on the microscopic behavior and mechanical performance of AlSi5Cu3 alloy was investigated. The AlSi5Cu3 alloy was cast in the metal and sand molds with equal cavity size and the characteristics of castings were evaluated. The metallographic analysis revealed that, due to the rapid solidification, the number of grains is 2.17% higher and the grain area is 3.71% less compared to sand mold casting. Moreover, due to the formation of more refined grain structures, metal mold casting has greater mechanical properties compared to sand mold casting. The findings revealed that the hardness, ultimate tensile strength (UTS), and impact strength of metal mold casting samples were improved by 8.82%, 10.74%, and 12.5% compared to sand mold casting samples.

Design and Analysis of Ventilated Disc Brake by Using Different Materials: A Review

Abstract: Disc rotor is component which is used in automotive vehicle wheels to apply brakes, the concept which works during brake is frictional resistance between pad and rotor. Due to frictional resistance the heat gets generated between disc and pad so, in order to reduce the effect of heat the rotor is designed as ventilated disc. The common material which is used to manufacture the disc rotor is Grey Cast Iron. The purpose of this review paper is to study the behavior and kinds of work has been done before on Disc Brake and based on this review paper we have decided to do structural analysis on disc brake rotor using different materials like GREY CAST IRON, TITANIUM, MAGNESIUM ALLOY, ALUMINUM ALLOY, and STRUCTURAL STEEL and then compare the results of different materials with conventional material (GREY CAST IRON) that is usually used in disc brake rotor. The analysis will be done by using CATIA for modeling and ANSYS WORKBENCH 18.0 for structural analysis. Based on previous research the objective of this review paper is “Design and analysis of ventilated disc brake by using different materials”

Impact of Processing Conditions on the Fluidity and Consistency of GISS-Processed Semi-Solid Aluminum Alloys

GISS (Gas Induced Superheated Slurry) is one of the more popular processes for the production of commercial semi-solid castings. For the successful production of high-quality castings, it is necessary to understand the impact of processing parameters on the flow behavior of the semi-solid metal. This paper describes the results of laboratory studies to examine the effects of processing conditions on the development of semi-solid feed material during GISS processing for two aluminum casting alloys, ADC12 and A356. Two series of tests were performed. The first involved a simple pouring test along an inclined section of a v-channel, to determine if differences in flow behavior could be identified. The second series of trials examined the effect of processing temperature and time on the consistency and flow behavior of the aluminum alloys. Ladles of molten aluminum alloy were treated using the GISS process at different temperatures for between zero and 10 seconds. After the treatment, the alloy was allowed to further cool in the ladle into the semi-solid temperature range, at which time the flow behavior of was compared. Consistency more suited to semi-solid casting was obtained when the GISS treatment temperature was lower and treatment time longer.

Microstructural evolution and corrosion mechanism of micro-alloyed 2024 (Zr, Sc, Ag) aluminum alloys

The 2024 aluminum alloy has excellent mechanical and low corrosion due to the existence of the high Cu levels, which shortens its service life. In this paper, we have systematically investigated the mechanism of the influence of three elements (Sc, Zr, and Ag) on the microstructure and corrosion behavior of 2024 aluminum alloy after microalloying. The results showed that microalloying treatment of 2024 aluminum alloy reduced the dendritic spacing of cast aluminum alloy; decreased the sizes of Cu-rich intermetallic particles (Cu-IMPs) within the peak aging of the T6 alloy to make their distribution more uniform; and changed the grain boundary phases (GBPs) and precipitate-free zones (PFZs) width of the T6 alloy. Microalloying treatment significantly changed the corrosion resistance of the alloy. Both Zr and Ag elements significantly improved the corrosion resistance of the alloy and reduced IGC depth and electrochemical corrosion rate, however, the Sc elements deteriorated the corrosion resistance of the alloy. Moreover, the corrosion mechanism of the alloy was also discussed in detail.

Microstructure features induced by fatigue crack initiation up to very-high-cycle regime for an additively manufactured aluminium alloy

Fatigue failure can still occur beyond 107 cycles, i.e. very-high-cycle fatigue (VHCF), in many metallic materials, such as aluminium alloys and high-strength steels. For VHCF of high-strength steels, a fine granular area (FGA) surrounding an inclusion is commonly identified as the characteristic region of crack initiation on the fracture surface. However, no such FGA feature and related crack initiation behaviour were observed in VHCF of conventionally cast or wrought aluminium alloys. Here, we first reported the distinct mechanisms of crack initiation and early growth, namely the microstructure feature and the role of FGA in VHCF performance for an additively manufactured (AM) AlSi10Mg alloy. The AM pores play a key role in fatigue crack initiation similar to that of the inclusions in high-strength steels, resulting in almost identical FGA behaviour for different materials under a range of mean stress with a stress ratio at R < 0 or R > 0. The profile microstructure of FGA is identified as a nanograin layer with Si rearrangement and grain boundary transition. This process consumes a large amount of cyclic plastic energy making FGA undertake a vast majority of VHCF life. These results will deepen the understanding of VHCF nature and shed light on crack initiation mechanism of other aluminium and AM alloys.

Mechanical and Microstructural Investigations on a Symmetric Mould Processed with Semi-Solid Aluminum RheoMetal&lt;sup&gt;TM&lt;/sup&gt;: Analysis of the As-Cast Proprieties

High-pressure die-casting (HPDC) can be a productive process for high-quality cast aluminium alloy components. However, it is also a process prone to generate defects, such as gas porosities and incomplete fillings, resulting in rejections. One way to reduce the reject rate is to employ Semi-Solid Metal processing with HPDC. The most important advantages of Semi-Solid alloys are reduced shrinkage defects, fewer gas porosities, and fewer chances of filling-related problems. To take full advantage of a semi-solid metal slurry, the casting process must be controlled meticulously to reach homogeneous casting quality and high process repeatability. A study has been conducted on cast parts composed of two-dimensional symmetrical cavities. From the mechanical tests, unexpected differences emerged in both tensile strength and fracture elongation, which were confirmed by differences in the microstructure. The paper investigates the reasons for the asymmetry in the proprieties to avoid similar problems in future studies and maximize the effectiveness and repeatability of the high-pressure die-casting process.

The Effect of Solution Temperature on Microstructure Evolution and Mechanical Properties of a Low-Silicon Cast Aluminum Alloy Containing Mn

The Effect of Solution Temperature on Microstructure Evolution and Mechanical Properties of a Low-Silicon Cast Aluminum Alloy Containing Mn

Strengthening mechanisms and work hardening in a heterostructured cast aluminum alloy under compressive loading: Correlation with nanomechanical properties

The compressive deformation behavior of a high-pressure die-cast Silafont®-36 aluminum alloy was evaluated in relation to the microstructural changes during deformation. No strain rate sensitivity was observed for the alloy compressed at room temperature. The as-cast microstructure consisted of softer primary α-Al dendrites and harder Al-Si eutectic structure, which was well depicted by the difference in the nanohardness values using high-speed nanoindentation mapping. The load-bearing capacity of eutectic Si particles and thermal mismatch enhanced dislocation density strengthening were identified to be the predominant strengthening mechanisms in the alloy, plus a certain degree of Orowan strengthening mechanism. The work hardening capacity of the cast alloy was mainly attributed to the increase in the dislocation density in the softer α-Al matrix, which was further assisted by the presence of eutectic Si particles. The relative increase in the flow stresses also corresponded well to that in the nanohardness values of the α-Al grains with increasing strain levels.

Influences of Ni Addition on Microstructure and Mechanical Properties of Cast Aluminum Alloy 207

Influences of Ni Addition on Microstructure and Mechanical Properties of Cast Aluminum Alloy 207

Consumable additive FDM models in the production of aluminum alloy castings

This article describes the results of a study aimed at improving production technology of experimental castings from aluminum alloys by investment casting using models produced by 3D printing. The consumable models were produced using fused deposition modeling (FDM). Biodegradable polylactide (PLA) was used as a material for the models. In order to decrease the surface roughness of consumable PLA model. chemical post-treatment by dichloromethane needs to be performed. After immersion of the model into the solvent for 10s, its surface becomes smooth and glossy. Three-point static bending tests of PLA plates demonstrated a mechanical strength of average ~45.1 MPa. A thermomechanical analysis of polylactide demonstrated that in the course of heating of ceramic shell in excess of 150 °C, the polylactide model begins to expand intensively by exerting significant pressure on the ceramic shell. In order to decrease stress during the removal of polylactide model from ceramic mold, the heating time in the range of 150–300 °C needs to be heated to a maximum. The use of hollow consumable casting models with a cellular structure not higher than 30 % is also sensible. The stresses on the shell will not exceed its strength. Characteristic temperature properties of PLA plastic thermal destruction were detected using thermogravimetric analysis. Polylactide was established to completely burn out upon heating to 500 °C leaving no ash residue. Analysis of the results identified the burning modes of polylactide models from ceramic molds. Using a Picaso 3D Designer printer (Russia), the PLA models were printed used for production of experimental castings from aluminum alloys. It was revealed that the surface roughness (Ra) of a casting produced using a consumable model treated by dichloromethane decreases by 81.75 %: from 13.7 to 2.5 μm.

Effects of ErF3 Particles on the Structure and Physicomechanical Properties of A359 Alloy

In this work, the impact of ErF3 submicroparticles on the microstructure and mechanical properties of the A359 alloy was studied. ErF3 particles provided a homogeneous structure in castings produced via the casting method. The modifying effect of ErF3 particles on the structure of Al–Si alloys is realized through the mechanism of restraining the crystallization front and is achieved through the reduction in the formation of clusters of iron phases and eutectic lamellar silicon. It was found that the addition of 1 wt% ErF3 to the A359 alloy leads to a decrease in the average grain size by 21% and an increase in the yield strength by 14%, in tensile strength by 16%, in the microhardness of Al15(FeMn)3Si2 phase by 34% and in the Al15(FeMnCr)3Si2 phase by 7%. The heat treatment of the A359 alloy with ErF3 particles increased the yield strength by 36% and the tensile strength by 34%. The absence of an effect of ErF3 particles on the hardness values of the A359 alloy, as well as on the fracture process of the A359 alloy, was observed. The negative influence of ErF3 particle agglomerates and clusters on the strength characteristics of the investigated alloys was observed. Approaches for further exploring the potential of ErF3 particles as a strengthening phase in cast aluminum alloys of the Al–Si system were proposed.

Precipitating thermally reinforcement phase in aluminum alloys for enhanced strength at 400 °C

Heat-resistant aluminum alloys are widely used in aerospace and automotive fields for manufacturing hot components due to their advantages in lightweight design and energy conservation. However, the high-temperature strength of existing cast aluminum alloys is always limited to about 100 MPa at 350 °C due to coarsening and transformation of strengthening phases. Here, we reveal that the yield strength and ultimate tensile strength of the T6 state Al–8.4Cu–2.3Ce–1.0Mn–0.5Ni–0.2Zr alloy at 400 ℃ increase by 34% and 44% after re-aging at 300 °C for 100 h, and its thermal strength exhibits distinguished advantage over traditional heat-resistant aluminum alloys. The enhanced elevated-temperature strength is attributed to the reprecipitation of the Ni-bearing T-Al20Cu2Mn3 phase, whose number density increases over one time. The significant segregation of Ni, Ce, and Zr elements at the interfaces helps improve the thermal stability of the T phase. The thermostable T phase effectively strengthens the matrix by inhibiting dislocation motion. Meanwhile, a highly interconnected 3D intermetallic network along the grain boundaries can still remain after long-term re-aging at 300 °C, which is conducive to imposing a drag on the grain boundaries at high temperatures. This finding offers a viable route for enhancing the elevated-temperature strength of heat-resistant aluminum alloys, which could provide expanded opportunities for higher-temperature applications.

Development of Inoculants for Aluminum Alloy: A Review.

Aluminum and its alloys are widely used in packaging, transportation, electrical materials, and many other fields because of their abundance, light weight, good mechanical properties, suitable corrosion resistance, excellent electrical conductivity, and other advantages. Grain refinement achieved by adding inoculant is important not only to reduce the segregation and thermal cracking of alloy castings but also to improve the mechanical properties of alloy castings. Therefore, fine equiaxed grain structure has always been one of the goals pursued by the aluminum alloy casting industry. For this reason, the selection and development of effective inoculants for aluminum alloy is a key technology in the aluminum processing industry. This paper summarizes the development history of inoculants for aluminum alloy, including Al-Ti-C, Al-Ti-B, Al-Ti, Al-Ti-B-(C)-Ce, Al-Sc, and the Fe-rich phase of Al-Si alloy. At the same time, the advantages and disadvantages of common inoculants are introduced and prospective future applications are reviewed.