ADC12 Aluminum Alloy Research Articles

Salt spray corrosion and electrochemical corrosion property of anodic oxide films on ADC12 aluminum alloy

Anodic oxide films were prepared by anodic oxidation on the surface of ADC12 aluminum alloy and their corrosion properties were explored. The original samples, anodized samples, and sealed samples were placed in the salt spray corrosion chamber and were taken out at different times. Then the corrosion resistance of the ADC12 aluminum alloy was discussed, and the electrochemical corrosion test was researched. The results indicated that the surface of the original samples reveals many large-area pits after salt spray corrosion, while the sealed samples present a smoother surface. The dense oxide films on the surface of the base metals effectively prevent Cl[Formula: see text] entering into aluminum alloys especially after sealing. Electrochemical tests including the potential polarization curve and electrochemical impedance spectroscopy (EIS) as functions of exposure time were employed to reveal the corrosion behavior of surface layers. After the sealing treatment on the oxide films, the corrosion potential moved in the positive direction, the corrosion current density decreased, and the corrosion resistance of the ADC12 aluminum alloy was significantly improved.

Effect of vacuum system on porous product defects and micro structures on the ADC-12 aluminum material with cold chamber die casting machines

Research on the effect of the vacuum system on porous product defects and microstructure on the ADC-12 aluminum alloy material with cold chamber die casting machine has been carried out. In the injection process in cold chamber die casting, the aluminum material commonly used is namely ADC-12. The ADC-12 aluminum alloy has better resistance to corrosion, is lightweight, has ease of casting, good mechanical properties, and dimensional stability. The purpose of this study is to compare the vacuum system with overflow system using ADC-12 aluminum alloy material with observed parameters are porosity, trapped air pressure, hot spot level, hardness level of Vickers Hardness, XRD analysis, and microstructure analysis with Light Optical Microscope (LOM). The results of the analysis using the Magma flow software, the vacuum system is better than the overflow system in terms of porosity and product yield, which is influenced by the amount of air trapped and the hot spot level. The level of hardness in a product with a vacuum system is better than a product with an overflow system. The average hardness in the vacuum system is 162,235 while in the overflow system is 147,615. Thus, the use of a vacuum system can increase the level of hardness in products by around 9%. With the change in usage from the overflow system to the vacuum system, it shows an increase in dislocation density followed by an increase in lattice strain and a decrease in the level of crystal size of the product.

The Research of Tool Wear Mechanism for High-Speed Milling ADC12 Aluminum Alloy Considering the Cutting Force Effect.

Tool wear is a major cause of accelerated tool failure during the milling of aluminum alloy. The periodically cutting force directly affect the cutting heat and tool wear due to the intermittent cutting characteristics of the milling process. The focus of this paper is to analyze the influence of the variation of cutting force on tool wear behavior. The change law of cutting force by cutting parameters was analyzed firstly. Secondly, the variation of the wear land width (VB) of tool flank face by the milling length was analyzed. Thirdly, the wear morphology and the energy dispersive spectrometer (EDS) results of tool rake face and flank face in different cutting parameters were observed by tungsten filament scanning electron microscope. Finally, considering the cutting force effect, the tool wear mechanism during high-speed milling of Aluminum-Alloy Die Castings 12 (ADC12, 12 means aluminum number 12) was analyzed. The cutting force in tangential direction is predominant during high-speed milling aluminum alloy, which decreases gradually with the increase of cutting speed but increases gradually with the feed rising. The adhesion-oxidation wear was main wear mechanism of tool rake face during high-speed milling. While adhesive wear was the main wear mechanism of the tool flank face during high-speed milling. It is found that the formation of adhesive wear is the process from particle adhesion to melting until the formation of adhesive layer, which related to the change of cutting force.

An Improved Johnson–Cook Constitutive Model and Its Experiment Validation on Cutting Force of ADC12 Aluminum Alloy During High-Speed Milling

Because of the massive work and high cost of milling experiments, finite element analysis technology (FEA) was used to analyze the milling process of ADC12 aluminum alloy. An improved Johnson–Cook (J–C) constitutive equation was fitted by a series of dynamic impact tests in different strain rates and temperatures. It found that the flow stress gradually increases as the strain rate rises, but it decreases as the test temperature rises. Compared with the J–C constitutive model, the predicted flow stress by the improved J–C constitutive model was closer to the experimental results when the strain rate was larger than 8000 s−1 and the temperature was higher than 300 °C. A two-dimensional cycloidal cutting simulation model was constructed based on the two J–C constitutive equations which was validated by milling experiments at different cutting speeds. The simulation results based on the improved J–C constitutive equation were closer to the experimental results and showed the cutting force first increased and then decreased, with cutting speed increasing, reaching a maximum at 600 m/min.

Chip morphology and cutting temperature of ADC12 aluminum alloy during high-speed milling

The ADC12 aluminum alloy is prone to severe tool wear and high cutting heat during high-speed milling because of its high hardness. This study analyzes the high-speed milling process from the perspective of different chip morphologies. The influence of cutting temperature on chip morphology was expounded. A two-dimensional orthogonal cutting model was established for finite element analysis (FEA) of high-speed milling of ADC12 aluminum alloy. A theoretical analysis model of cutting force and cutting temperature was proposed based on metal cutting theory. The variations in chip shape, cutting force, and cutting temperature with cutting speed increasing were analyzed via FEA. The results show that, with the increase in cutting speed, the chip morphology changes from continuous to serrated, and then back to continuous. The serrated chip is weakened and the cutting temperature is lowered when the speed is lower than 600 m·min−1 or higher than 1800 m·min−1. This study provides a reference for reducing cutting temperature, controlling chip morphology and improving cutting tool life.

Corrosion Behavior of Diecast Mg–Al–Mn–Ca–Si Magnesium Alloy

The corrosion behavior of diecast Mg–Al–Mn–Ca–Si (AMXS6020) magnesium alloy with superior flame-retardance and heat-resistance was systematically investigated and compared to diecast AZ91D magnesium alloy and ADC12 aluminum alloy by salt spray test, cyclic corrosion test, electrochemical experiment, scanning electron microscopy and energy dispersive X-ray spectroscopy. The results showed that AMXS6020 alloy had a higher corrosion resistance than AZ91D and ADC12 alloys. The superior corrosion resistance of AMXS6020 alloy was attributed to netlike eutectic structure consisting of (Al, Mg)2Ca and α-Mg, which could hinder the corrosion growth. The barrier effect of netlike (Al, Mg)2Ca phase structure on corrosion growth was also confirmed by potentiodynamic polarization.

Influence of Artificial Aging on the Dry Sliding Wear Behavior of ADC12 Alloy-B4C-Rice Husk Ash Particulates Reinforced Hybrid Composites

The influence of artificial aging on the wear behavior of ADC12 alloy reinforced with Boron carbide (B4C) and Rice Husk Ash (RHA) composites have been investigated. Hybrid composites with 5 wt. % of B4C fortification constant and variable quantity of rice husk ash particles in steps of 9 and 12 wt. % in the ADC12 alloy prepared by melt stir process. ADC12 aluminium alloy, ADC12 alloy-5 wt. % B4C-9 wt. % RHA and ADC12 alloy-5 wt. % B4C-12 wt. % RHA Samples were solutionized at a temperature of 525˚C for 1 h. Further, these solution heat treated samples were artificially aged at the temperature of 175˚C for 10 h. Microstructural characterization was carried out by using SEM and EDS. A pin-on-disc wear testing machine was utilized to assess the wear loss of specimens, in which a solidified EN32 steel plate was utilized as the counter face. Wear tests were accompanied on ADC12 alloy, ADC12 alloy-5 wt. % B4C-9 wt. % RHA and ADC12 alloy-5 wt. % B4C-12 wt. % RHA hybrid composites at varying loads of 10 N, 20 N and 30 N with varying sliding distances of 250 rpm, 500 rpm and 750 rpm for constant sliding distance of 1000 m. The wear resistance of ADC12 alloy enriched with the accumulation of B4C and RHA particulates. Further, heat treated samples were exhibited the superior wear resistance as compared to the base alloy and un-heat treated samples.

Optimization of Pouring Temperatures and Stirrer Speed Parameters on a Semi-Solid Slurry of ADC12 Al Alloy Prepared by Mechanical Stirring

This paper presents an experimental design approach for the optimization process parameters for the aluminum solid alloy casting of ADC12 alloys. To achieve this goal, the pouring temperatures and stirring speed are selected and two levels of this parameter are considered. Design of expert (DOE) of tests was used for experimental design and analysis of results. The aluminum ADC12 slurry is stirred by a mechanical stirrer (round rods stirrer models) with a variation of speed 250, 300, 350 rpm for 20 seconds. Furthermore, the aluminum slurry of ADC12 is poured on a metal mold with a temperature of 620 °C, 600 °C, and 580 °C. The microstructure characteristics were examined by direct observation using optical microscopy, secondary α-Al phase dendrite arm spacing and shape factor were identified. The mechanical properties were investigated by the hardness test and tensile test. The mechanical properties and microstructure of aluminum alloys ADC12 made with semi-solid rheocasting casting technology using several parameters pouring temperature and stirring speed have been studied, and the results obtained can be synergized as follows. ADC12 aluminum alloy slurry preparation using a round rod mechanical stirrer on semi-solid casting can improve mechanical properties. Low pouring temperature and high stirring speed are reliable techniques for producing the right mechanical and microstructure properties for a semi-solid casting process (Rheo casting). The pouring temperature and stirring speed are recommended to produce optimal mechanical properties and the round microstructure is 580 °C and 350 rpm.

An Extended Iterative Identification Method for the GISSMO Model

This study examines an extended method to obtain the parameters in the Generalized Incremental Stress State Dependent Damage (GISSMO) model. This method is based on an iterative Finite Element Method (FEM) method aiming at predicting the fracture behavior considering softening and failure. A large number of experimental tests have been conducted on four different alloys (7003 aluminum alloy, ADC12 aluminum alloy, ZK60 magnesium alloy and 20CrMnTiH Steel), here considering tests that span a wide range of stress triaxiality. The proposed method is compared with the two existing methods. Results show that the new extended Iterative FEM method gives the good estimate of the fracture behaviors for all four alloys considered.

Effect of rare earth Yb on microstructure and corrosion resistance of ADC12 aluminum alloy

Optical microscopy, scanning electron microscopy, energy dispersive spectrometer, and X-ray diffractometer were used to study the effect of rare earth Yb (0, 0.3, 0.6, 0.9, and 1.2 wt%) on microstructure and corrosion resistance of ADC12 aluminum alloy. The results showed the α-Al, eutectic Si and β-Al5FeSi phase in the alloys with addition of rare earth Yb were obviously refined. The Al3Yb intermetallic compound was also observed with 0.9 wt% Yb addition. The immersion and electrochemical test results showed that the corrosion current density (1.27 μA cm−2) of the 0.9 wt% Yb modified alloy was 84.7% lower than that of matrix (8.302 μA cm−2), corresponding weight loss rate of the alloy shows a minimum value for 46 μg cm−2 day−1. Formation of Al3Yb on the cathode Si hindered the growth of the Si phase, which suppressed the corrosion activity of the cathode region and decreased the rate of micro-galvanic corrosion.

Effect of rare earth elements on the microstructure and properties of a die-cast aluminum alloy

Abstract The effects of the rare earth elements Ce, La and Sm on the microstructure and mechanical properties of a die-cast aluminum alloy were studied. First, the optimal percentage content of the main elements in the alloy was determined by a single factor and by orthogonal experiments based on the composition range of ADC12 aluminum alloy. The results showed that the optimal percentage content of the main elements in ADC12 die-cast aluminum alloy were 11 wt.-% Si, 2.5 wt.-% Cu, 0.5 wt.-% Mn and 0.3 wt.-% Mg. The tensile strength was 285 MPa and the fracture strain 2.23 %. Then, three rare earth elements of varied contents were added to the above-mentioned aluminum alloy. The tensile strength and elongation of the alloy were increased through the addition of rare earth elements. The comprehensive mechanical property of the alloy was best when Ce, La and Sm levels were at 0.6, 0.4 and 0.2 wt.-%, respectively, in the single factor test. Sm had the largest influence on the comprehensive mechanical properties of the alloy, followed by Ce and La which had the least influence.

Development of Slurry Preparation Method by Applying Mechanical Vibration

The preparation of a semi-solid slurry with fine and spherical solid particles dispersed in the liquid phase is a key technology for the semi-solid process. In this study, we have developed the slurry preparation method by applying mechanical vibration for JIS AC4CH (equivalent to A356 in the ASTM standard) and ADC12 (equivalent to A383 in the ASTM standard) aluminum alloys. In this method, the mechanical vibration was applied to the aluminum alloys during cooling from a liquid state to semi-solid state. The shape of the particle was varied by controlling vibration conditions. Therefore, we investigated the effect of conditions on mechanical vibrations. There are four parameters which are frequency, acceleration amplitude, velocity amplitude and displacement amplitude in the mechanical vibration. Among these parameters, the velocity amplitude had highest effects on the shape of solid particles. By properly controlling of the frequency and the velocity amplitude, the slurry with fine and spherical solid particles could be obtained. Moreover, the fraction solid of slurry could be controlled by varied initial liquid temperature. Especially, ADC12 aluminum alloy has low liquid-solid coexistence temperature range, so it is not considered to be suited for the semi-solid process. However, by using this mechanical vibration method, the semi-solid slurry could be obtained stably. This method is expected to be effective for the semi-solid high-pressure die-casting process.

Effect of Trace Yttrium Addition and Heat Treatment on the Microstructure and Mechanical Properties of As-Cast ADC12 Aluminum Alloy

The effects of rare earth yttrium (Y) additions and the heat treatment process on the microstructure and mechanical properties of as-cast ADC12 aluminum alloy have been investigated. The results showed that the primary Si crystals were significantly refined from long axis to fibrous or granular when the Y content was 0.2 wt%. Compared to the matrix, the mean area and aspect ratio were decreased by 92% and 75%, respectively. Moreover, the Si and Fe-rich phases were spheroidized and refined with a small average size during the solid solution. It was also noted that the copper-rich phases were dissolved into the matrix. Correspondingly, it was found that after metamorphic and heat treatment the ultimate tensile strength (UTS), elongation, and, hardness increased by 81.9%, 69.7%, and 74.8%, respectively, compared to the matrix. The improved mechanical properties can primarily be attributed to the optimization of the microstructure and the refinement of various phases.

Evaluation of Face Milling Operation Parameters on Surface Roughness of Crankcase Housing by Two Level Factorial Design with Center Points

In this study, there are three machining parameters consist of spindle speed, feed rate and depth of cut which were conducted through full factorial with four center points to determine the effect of machining parameters on the surface roughness and verify whether there is curvature in the model for CNC face milling process in an automotive components manufacturer in Thailand. The workpieces used semi-solid die casted ADC12 aluminum alloy crankcase housing which they were performed by the ARES SEIKI model R5630 3-axis CNC vertical machining center and face milling cutter with diameter of 63 millimeters. The surface roughness of face-milled was measured by the surface roughness tester. It was found that the greatest main effect influence to surface roughness was spindle speed, followed by feed rate and depth of cut at significance level of 0.05.

The effects of heat treatment on microstructure and mechanical properties of rheocasting ADC12 aluminum alloy

The effects of heat treatment on microstructure and mechanical properties of rheocasting ADC12 aluminium alloy produced by gas induced semi-solid (GISS) technique were studied. The solution heat treatment performed at the temperature of 520°C under various solution treatment times for 2, 4, 6, 8, 10, and 12 h and followed by water quenching at room temperature. The results show that the optimum solution heat treatment condition for the non-dendritic structure of ADC12 aluminium alloy was 520°C for 8 h. The age hardening was also carried out at 170°C for different aging times of 6, 8, and 10 h, respectively. It was found that the artificial aging at 170°C for 6 h was sufficient to achieve the highest hardness of 73.2 HRB. This was due to the appropriate refinement of acicular eutectic structure.

Continuum damage mechanics based approach to the fatigue life prediction of cast aluminium alloy with considering the effect of porosity

A damage mechanics based approach is applied for the study of fatigue behaviour of high pressure die cast ADC12 aluminium alloy. A damage coupled elastoplastic constitutive model is presented according to the concept of effective stress and the hypothesis of strain equivalence. An elastic fatigue damage model taking into account the pore-induced stress concentration is developed to investigate fatigue damage evolution of the specimens subjected to cyclic loading. The predicted lives for the specimens with different sizes of pores are consistent with the experimental data. The pore-induced fatigue damage and the variation of fatigue life along with the size of pores are also investigated.

Reinforced lubrication of vegetable oils with graphene additive in tapping ADC12 aluminum alloy

This paper studied the effect of graphene additive on the lubricating capacity of vegetable oils. The castor oil, rapeseed oil, and corn oil were chosen as base oils, and ultrasonic agitation was used to prepare the graphene in vegetable oil suspensions with six different mass fractions. These suspensions were utilized as minimum quantity lubrication (MQL) lubricants during the internal tapping process of ADC12 aluminum alloy. Tapping torque and thread surface morphology analyses were applied to evaluate the lubrication performance. The results showed that the pure castor oil MQL achieves the lowest average tapping torque in all the base oils. Meanwhile, the use of graphene additive can significantly reduce the tapping torque, and this torque reduction shows a nonlinear relationship with the graphene mass fraction. As an overall trend, the 0.5% mass fraction is the optimum concentration, which decreased the average torque by 0.64 Nm (11.4%), 1.6 Nm (16.4%), and 1.7 Nm (17.7%) compared with pure castor oil, rapeseed oil, and corn oil, respectively. Moreover, the scratching defects on the thread surface were obviously reduced with the application of graphene additive. This torque-reducing and anti-wear effect could be related with the graphene-related friction films formed on the metal surfaces. The research verified that the vegetable oil-based graphene suspension can be used as a substitute for the conventional mineral oil-based metalworking fluids.

Experiments and FEM simulations of fracture behaviors for ADC12 aluminum alloy under impact load

Using the combination of experiment and simulation, the fracture behavior of the brittle metal named ADC12 aluminum alloy was studied. Five typical experiments were carried out on this material, with responding data collected on different stress states and dynamic strain rates. Fractographs revealed that the morphologies of fractured specimen under several rates showed different results, indicating that the fracture was predominantly a brittle one in nature. Simulations of the fracture processes of those specimens were conducted by Finite Element Method, whilst consistency was observed between simulations and experiments. In simulation, the Johnson- Cook model was chosen to describe the damage development and to predict the failure using parameters determined from those experimental data. Subsequently, an ADC12 engine mount bracket crashing simulation was conducted and the results indicated good agreement with the experiments. The accordance showed that our research can provide an accurate description for the deforming and fracture processes of the studied alloy.

Effects of Metal Anion Complexes in Electrolyte on the Properties of Anodic Oxide Films on ADC12 Al Alloy

The anodization of ADC12 aluminum alloy was investigated in the metal anionic acid media. Anodic oxide films containing foreign elements were formed on ADC12 Al alloy by anodization in the anion complex solution. Furthermore, the rough surface and cracks were considerably smoothened by the deposit of metal anions. When the size of metal anion was small, relatively large amount of metal anions was loaded in anodic films. Existence of <TEX>$MoO_3$</TEX>, <TEX>$TiO_2$</TEX> and MgO was confirmed by XPS. According to the results of Tafel analysis, Mo oxide represented the most noble anti-corrosion potential due to <TEX>$MoS_2$</TEX> formation. Corrosion current densities were generally higher than that of pristine anodic oxide without anion complexes.

Investigation of Solidification Process of As-Cast ADC12 in Sand Molds with Different Pouring Conditions by Temperature Field

An investigation of solidification process of as-cast ADC12 aluminum alloy in sand molds with different pouring conditions by temperature field was discussed in the present study. The ADC12 aluminum alloy was investigated in quarzt sand mold and chromite mold using sodium silicate binder with hardening by CO2 gas under atmospheric and low vacuum conditions. Mechanical properties results indicated that a chromites mold under low vacuum condition has the optimal value. Thermal diffusivity was determined by finite difference method. The maximum thermal diffusivity was obtained in a chromite mold under low vacuum condition and correspondence to the minimum solidification time field.