Commercial Purity Aluminum Research Articles

Fabrication of in situ aluminium matrix composite by change in addition sequence of MnO 2 particles

In-situ composite of commercially pure aluminium (CPA) matrix and 1 to 4 wt% MnO 2 reinforcement particles were fabricated using stir casting method. 3 wt% Mg was added to improve the wettability of generated in situ phases in CPA matrix. MnO 2 additions were carried out in two sequences named as A and B. In sequence A, MnO 2 was added after melting of CPA with 3 wt% Mg while in sequence B, MnO 2 added before melting of CPA with 3 wt% Mg. The sequence of addition of MnO 2 has been studied in terms of recovery of Mn, mechanical properties and microstructures of fabricated composite. Maximum recovery of Mn obtained in case of sequence B. Improved results in microstructure and mechanical properties were found in sequence B compared to sequence A. Formation of in situ phases such as MnAl 6, MgSiO 3, Al 2 O 3, cemented carbide Mn 3 AlC and small quantity of MgFeSiO 3, were confirmed by Xy diffraction analysis in final composite materials.

TiCヘテロ凝固核粒子添加による工業用純アルミニウム積層造形体の組織微細化

TiCヘテロ凝固核粒子添加による工業用純アルミニウム積層造形体の組織微細化

Microstructure of Commercial-Purity Aluminum Sheets Processed by Accumulative Roll Bonding (ARB) at a Series of Cyclic Preheating Conditions

Microstructure of Commercial-Purity Aluminum Sheets Processed by Accumulative Roll Bonding (ARB) at a Series of Cyclic Preheating Conditions

Improving Discharge Voltage of Al-Air Batteries by Ga3+ Additives in NaCl-Based Electrolyte.

The application of NaCl-based aluminum-air batteries is limited due to the passivation of the aluminum anode. In an effort to solve this problem, this work studied the influence of different concentrations of Ga3+ additives on the discharge behavior of Al in the NaCl electrolyte. The results of both experiments and theoretical calculations have shown that commercial purity aluminum could be significantly activated by Ga3+. Based on microstructure observations and electrochemical impedance spectroscopy, the influence activation mechanism of Ga3+ on the discharge behavior of commercial purity Al is clarified. The addition of Ga3+ biased the surface charge of aluminum along the activation direction, forming activation sites, and then destroyed the surface passivation film. Due to the formation of a gallium–aluminum amalgam, the Al-air battery had the best discharge characteristics in the electrolyte with 0.2 M Ga3+, and its discharge voltage reached 0.9734 V with a remarkable increase compared with that of NaCl solution (0.4228 V). Therefore, Ga3+ additive is a promising choice for NaCl-based Al-air batteries to improve their discharge voltage.

Grain Refining of Aluminium and 6063 Alloys Using Al-V Alloy Containing Al3V Intermetallic Compound

The grain refinement of aluminium alloys is one of the important processes in various industrial fields. This work aims to use aluminium-vanadium (Al-V) master alloy as a new grain refiner for grain refinement of aluminium alloys. The new refiner was prepared by reduction of vanadium pentoxide V2O5 using molten aluminium, then it was examined using SEM, EDS, XRD, and optical microscopy. The findings of these tests indicated that the developed master alloy contains blocky-shaped particles evenly distributed within the aluminium matrix Al3V in the form of an intermetallic compound. Different levels of vanadium content were examined (3.5, 5.6, and 8.3) as grain refiners for commercial pure Al and 6063 alloys. It was found that the grain size was decreased from 2000 to 320 mm for commercial pure aluminium and decreased from 1500 to 300 mm for 6063 alloys. The best results were obtained by using vanadium content of 0.03 wt.% in the refined alloy and a holding time of 3 min. Based on the gross restriction factor (GRF), the new grain refiner Al-V master alloy performed well at vanadium contents more than 0.02 wt.% in the refined alloy.

Effect of Process parameters on Linear Friction welding of Commercial Grade Pure Aluminum

This paper investigated the effects of process parameters such as burn off distance, oscillating frequency, and forging pressure on linear friction welding of commercially pure aluminum. Friction welding (FW) techniques are a group of techniques that are based on frictional heat between components that occurs during movement while under pressure. Linear Friction welding is a solid-state process in which one part moves in a linear fashion at high speed and presses against another part that is held stationary. Linear friction welding (LFW) is a very well specialized technology used by global gas turbine engine manufacturers to create bladed disc assemblies. The sample bar with a cross section of 25mmx25mmx140mm was used for the experimental testing. The results were obtained by maintaining amplitude and frequency at 1.5mm and 40Hz, respectively, and forging pressure at 10MPa, 15MPa, and 20MPa. It is observed that, Lower HAZ. Burn-off distance grew as forging pressure increases with time.

A Correlation between Deformation-Induced Surface Roughness and In-Plane Plastic Strain in an Aluminum Alloy at the Mesoscale

Experimental and numerical studies on deformation-induced surface roughening in a commercial purity aluminum alloy are presented and discussed. Mesoscale surface profiles evolving in the experimental and numerical specimens in the course of tension are processed to reveal a correlation between roughness characteristics and in-plane plastic strains at the mesoscale. A dimensionless parameter calculated as a ratio of the rough profile length to the profile evaluation length has been used for quantitative estimations of the mesoscale roughness patterns. The dimensionless roughness parameter is shown to depend exponentially on the in-plane plastic strains at the mesoscale. The results support an early assumption that in-plane plastic strains accumulated in a loaded material can be evaluated from the estimations of mesoscale surface roughness.

STUDY OF ALUMINUM TUBE COLD NOSING PROCESS INTO CONICAL AND HEMISPHERICAL DIES

Theoretical analysis and finite element method were used to simulate the cold nosing process of commercial purity Aluminum tubes into conical and hemispherical dies. The influences of process parameters, namely initial tube wall thickness, conical semi-die angle and coefficient of friction were investigated. The results of the nosing process were obtained in terms of load-displacement curves, thickness distribution of deformed parts, the nosing ratios and strain distributions. According to these finding, the final shape and defects of the product can also be predicted. Experimental work was carried out to verify the simulation results. A new developed setup design was proposed to improve the product quality. Two adjacent punches were used: one with a front plunger and the other was an outer sleeve to constrain the tube. It could be observed that the load increase with increasing the tube wall thickness, semi die angle and coefficient of friction. The nosing ratio increases as wall thickness increases. Comparison between analytical and FE predictions to the experimental results showed good agreement.

MODELING AND ANALYSIS OF MACHINING PARAMETERS OF ECAP PROCESSED COMMERCIAL PURE ALUMINUM USING RSM AND ANN

Equal channel angular pressing (ECAP) processed materials have higher grain refinement and strength, and they exhibit more surface roughness when they are machined. This enhancement in the properties highly influences the surface roughness and material removal rate of the materials. The commercial pure aluminum has a wide variety of applications when it is enhanced with high strength properties. In this paper, the machinability of commercially pure aluminum processed through ECAP is investigated in turning operations. Different ECAP processes are carried out to study the microstructural characterization and mechanical properties of the material. The material removal rate and surface roughness are tested by performing the turning operation in the CNC lathe with chemical vapor deposited carbide tool such that the feed rate, spindle speed and depth of cut are considered as the machining variables. To create a hypothesis for the experimentation, the empirical models are developed for the objective functions using the statistical technique response surface methodology (RSM) such that the response models are the objective functions and the model variables are the machining parameters. The response models are verified for the adequacy through ANOVA and [Formula: see text]-test, and also verified for the closeness with the experimental results. Artificial neural network (ANN)-based empirical equations are also developed for the objective functions using the RSM design matrix and the results of both the RSM and ANN are compared for the suitability.

Effect of Waste Titanium Chips Addition Into the Aluminum Alloys on Their Microstructure

In the present study, turning chips were preferred to add titanium into liquid aluminum. Although being easy to reach and cheap, the chips were thought to be effective in minor titanium addition with their large surface area. Experimental studies have been carried out with A356 casting alloy and commercial purity aluminum. The effects of different process parameters were investigated on titanium transfer efficiency, microstructural and microhardness properties of the formed phases. The processes were carried out between 740 - 820 °C, for 2, 4, and 6 h, with the amount of added chips 5 and 10 wt.% (3 and 6 vol.%). The experiments were conducted with both commercially pure Al and A356 alloy. The microstructural investigations and microhardness measurements were carried out on the formed Al3Ti and (Al, Si)3Ti phases. The first noticeable result was that titanium transfer was more efficient in pure aluminum than in the A356 alloy. Also, it was observed that this difference became more significant with an increase in wt.% addition. The measured microhardness values were also differentiated depending on the Si content of the formed Al3Ti compound. Due to the presence of high Si content in A356 alloy, transference efficiencies of Ti were found highly limited compared to pure aluminum as the silicon enrichment in the Al3Ti compound reduces the diffusion of titanium and the growth rate of Al3Ti particles. Maximum transference efficiency was found 47.05% with 10 %wt. chip addition in commercially pure aluminum at the processing conditions of 780 °C for 4 h.

Effect of CeO2 Size on Microstructure, Synthesis Mechanism and Refining Performance of Al-Ti-C Alloy.

The effects of CeO2 size on the microstructure and synthesis mechanism of Al-Ti-C alloy were investigated using a quenching experiment method. A scanning calorimetry experiment was used to investigate the synthesis mechanism of TiC, the aluminum melt in situ reaction was carried out to synthesize master alloys and its refining performance was estimated. The results show that the Al-Ti-C-Ce system is mainly composed of α-Al, Al3Ti, TiC and Ti2Al20Ce. The addition of CeO2 obviously speeds up the progress of the reaction, reduces the size of Al3Ti and TiC and lowers the formation temperature of second-phase particles. When the size of CeO2 is 2–4 μm, the promotion effect on the system is most obvious. The smaller the size of CeO2, the smaller the size of Al3Ti and TiC and the lower the formation temperature. Al-Ti-C-Ce master alloy has a significant refinement effect on commercial pure aluminum. When the CeO2 size is 2–4 μm, the grain size of commercial pure aluminum is refined to 227 μm by Al-Ti-C-Ce master alloy.

A grain refinement mechanism of cast commercial purity aluminium by vanadium

Grain refinement of cast commercial purity aluminium by vanadium and the underlying mechanism have been investigated. Addition of 0.3 wt% and 0.4 wt% vanadium leads to columnar to equiaxed transition and the average grain sizes are refined to around 196 μm and 154 μm, respectively. Pro-peritectic equilibrium Al10V particles are identified near the grain centres. These Al10V particles have either octahedron or plate morphology with the bound planes belonging to {111} crystallographic planes. Three orientation relationships are also determined between the Al10V particles and aluminium grains. Crystallographic analysis based on the experimental orientation relationships indicates that the Al10V particles have relatively high nucleation potency for solid aluminium. Calculation of free growth undercooling based on the size distribution of the Al10V particles reveals that the relatively large size of Al10V particles facilitates the grain initiation of aluminium grains on these particles. Moreover, it is found that the level of vanadium added provides sufficient growth restriction effect in the aluminium melt as quantified by its growth restriction factor. All the three factors, i.e., sufficient potency of Al10V particles, relatively large size of the Al10V particles and adequate growth restriction effect by solute vanadium work in concert to achieve the grain refinement observed in Al-V alloys.

Effect of pH Change on the Electrochemical Behavior of Intermetallic Particles in AA1050 Aluminum

Commercial purity aluminum alloys, such as AA1050 and AA1100, are widely used for infrastructure and battery materials for their high formability, high electrical conductivity, and excellent corrosion resistance. The commercial purity aluminum alloys are known to contain Fe-rich intermetallic particles (IMPs). Although the IMPs are needed to provide the valuable properties, some of the IMPs could turn into an initiation site for pitting under salty environments. Since the Fe-rich IMPs show higher electrode potential than that of the Al-matrix, the IMPs work as a cathodic reaction site. As oxygen reduction reaction proceeds on the IMPs, the pH around the IMPs increases locally. The dissolution of the Al-matrix (often referred as trenching) is caused by the local alkalization, and a trench is formed around the IMPs. Crystallographic pitting is likely to be initiated inside the trench. Although the IMPs have an important role in trenching, the electrochemical behavior of the IMPs during trenching is still unknown. In this study, the dissolution behavior of the IMPs and surrounding Al-matrix was observed in situ using an optical microscopy in order to analyze the morphological change during trenching. The effect of pH change on the electrochemical behavior of the IMPs was analyzed using the bulk IMPs fabricated by arc-melting.

Improving the fracture toughness of multi-layered commercial pure aluminum via warm accumulative roll bonding

In this study, the fracture toughness of the multi-layered commercial pure aluminum samples (AA1050) prepared by warm accumulative roll bonding (WARB) was investigated for the first time. Based on the ASTM E561 standard, the R-curve method was utilized to measure the plane stress fracture toughness. Compact tension (CT) samples were prepared from the sheets that were processed by different ARB cycles. Mechanical properties, microstructure, and fracture surfaces of the CT samples were studied by uniaxial tensile test, electron backscatter diffraction (EBSD), and scanning electron microscopy (SEM), respectively. By increasing the number of WARB cycles, fracture toughness increased; after five cycles, 78% enhancement was observed compared to the pre-processed state. A correlation was seen between the fracture toughness variations and ultimate tensile strength (UTS). WARB enhanced UTS up to 95%, while the grain size showed a reduction from 35 to 1.8 μm. Measured fracture toughness values were compared with the room temperature ARB outcomes, and the effective parameters were analyzed. Fractography results indicated that the presence of tiny cliffs and furrows and hollow under fatigue loading zones and shear ductile rupture in the Quasi-static tensile loading zone.

The Interactions Between Oxide Film Inclusions and Inoculation Particles TiB2 in Aluminum Melt

In this work, a systematic study on the interactions between aluminum oxide films and TiB2 grain refiner particles and their effect on grain refinement behavior have been conducted. Oxide films were introduced into a commercial purity aluminum melt by adding AA 6061 alloy chips while the grain refiner particles were introduced by adding Al-3T-1B master alloy. Strong sedimentation of TiB2 grain refiner particles was observed in aluminum melt without chip addition during long-time settling. Most of the TiB2 particles were settled and accumulated at the bottom of crucible. In contrast, the sedimentation of TiB2 particles is much less in the melt with the addition of oxide films. A large fraction of TiB2 particles were found to be adhered to the oxide films located at the top part of the crucible, which inhibited the sedimentation of grain refiner particles. TP-1 type tests were also done to study the grain refinement efficiency of Al-3Ti-1B master alloy under different melt cleanliness and settling time. It is found that sedimentation of TiB2 particles greatly reduces the grain refinement efficiency. The introduction of oxide films seems to slightly alleviate the fading effect. This is owing to the strong adherence between the oxide films and TiB2 particles, which leads to a retardation of particle sedimentation.

Refining performance and recession of Al–TiO2–C–La2O3 refiners

Abstract Al–TiO2–C–La2O3 refiners were synthesized by the in-situ exothermic dispersion method using TiO2, C, Al and La2O3 powders as raw materials. Scanning electron microscopy equipped with energy dispersive X-ray spectrometry and X-ray diffraction were used to investigate the microstructures of the Al–TiO2–C–La2O3 refiners. Commercial pure aluminum was refined by the Al–TiO2–C–La2O3 refiners, aimed at investigating refining performance and the resistance to recession. The results show that the Al–TiO2– C–La2O3 refiner with 0.2% La2O3 is composed of α-Al, blocky Al3Ti, dispersive Al2O3 and TiC, which has a better refining effect on commercial pure aluminum than the Al– TiO2–C refiner. The average grain size refined by the above refiner is about 80 μm and it performs better and has a longer refining effect. The grain structure refined by Al–TiO2– C–La2O3 becomes finer within 5 min and remains the same after 120 min, while refined by the Al–TiO2–C refiner the equivalent times are 10 min and 30 min respectively.

Damping capacity of aluminium surface layers developed through friction stir processing

An attempt is made here to understand the role of tool rotational speed on the damping capacity of friction stir processed (FSP) commercial pure aluminium metal. The as-received metal plates were processed with a conical pin tool by keeping the tool traverse speed as constant and varying the rotational speed 600, 900 and 1200 rpm. Subsequently, samples extracted from the stir-zones were characterized for their microstructure, hardness, frequency-dependent and temperature-dependent damping capacities. The increase in rotational speed decreased the dislocation density and increased the average grain-size at the stir-zone, thus significantly influenced the damping capacity. The frequency-dependent damping capacity decreased with rotational speed owing to the reduction in dislocation density. High-temperature damping was significantly higher for the processed samples, but at the same time increase in rotational speed decreased the damping as there was an increase in grain size.

Closed-Die Forging of Gear Like Element.(Dept.M)

Closed die forging of spur gears is investigated using the slab method and the upper bound technique. The tooth regions are approximated by prismatic rectangular sections. The velocity field comprising three unit deformation regions is used. A constant frictional stress between workpiece and forging die is assumed. The average punch pressure normalized by the flow stress of the gear material is determined theoretically and compared with experimental results. The experimental work is carried out on a commercial pure aluminum (Al 1100) at room temperature. The forging process is carried out using one die geometry without using any additional blocker (preform) dies. The theoretical predictions of forging pressures and deformation configurations agree fairly well with the experimental results.

The effect of annealing temperature on the recrystallization and mechanical properties of severe plastic deformed commercial pure aluminium during ultra-fast annealing

In the research a commercial pure aluminium was cold rolled by 98% accumulative severe plastic deformation and then ultra-fast annealed at 350 °C−520 °C with the 1000 °C/s heating rate and 1.0 s holding time. The microstructure evolution and the mechanisms of the recovery and recrystallization for the above ultra-fast annealed pure aluminium were analyzed by Gleeble 3500 thermal simulation system, electron backscatter diffraction(EBSD),and transmission electron microscopy (TEM). For the ultra-fast annealing pure aluminum, the grain size increases from 2.05 μm to 17.10 μm with the increase of annealing temperature from 410 °C to 520 °C; the tensile strength of the annealed pure aluminium decreases from 116.48 MPa to 53.43 MPa, and the uniform elongation increases from 1.20% to 39.78%. When annealing at 410 °C, the storage energy was transformed into the driving force for grain nucleation, which greatly refined the grains. When annealing at 380 °C ∼ 410 °C, the pure aluminium is in the stage of recrystallization, and the average grain size refined to 2.05 μm. When annealing at 435 °C, the number of small-angle grain boundaries (<15°) was significantly reduced and the number of large-angle grain boundaries increased. When the annealing temperature increased to 470 °C or 520 °C, the crystalline grains had merged each other, leading to the grain size grow to 17.10 μm. The annealing temperature of ultra-fast annealing should be in the range of 410 °C to 435 °C for optimizing the mechanical performances of commercial pure aluminum.

Mechanical characterization and constitutive modeling of aluminum AA1050 subjected to high strain-rates

This work develops an elastic-viscoplastic constitutive formulation to the mechanical behavior of polycrystalline FCC metals subjected to high-strain-rate cold deformation, with application to aluminum AA1050. Following a phenomenological approach, the model can account for important macroscopic features related to the mechanical response of ductile metals subjected to high-velocity plastic deformations, such as: (i) strain-hardening; (ii) strain-rate-hardening; and (iii) instantaneous flow stress rate-sensitivity. As a novelty of this proposal, memory effects corresponding to past strain-rate history are considered to affect both the level and rate of material hardening. Another new aspect is the phenomenological representation of both the thermal activation and dislocation drag mechanisms influencing the instantaneous flow stress response. The model calibration and its validation are performed based upon experimental data for commercial pure aluminum AA1050 for wide strain and strain-rate ranges. In comparison with experiments, the proposed model provides suitable predictions for both continuous and sequential compression tests. Overall, due to its relative simplicity and constitutive capabilities, the proposed model proves to be a potential constitutive alternative to simulate engineering problems involving dynamic plastic deformations.