Aluminum Alloys, Processing and Characterization: Poster Session
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Yanjun Li, Norwegian University of Science and Technology

Tuesday 6:00 PM
February 28, 2017
Room: Hall B1
Location: San Diego Convention Ctr

I-1: Investigation of Structure and Properties of New Aluminum Alloys with Scandium: Mikhail Motkov1; Viktor Mann2; Alexander Krokhin2; Alexander Alabin2; Viktor Frolov2; Igor Kostin2; 1LLC "RUSAL ITC" ; 2LLC "RUSAL ITC"
    In the proposed work solved the problem of increasing the strength characteristics of conventional alloys such as 5083 vintage intended for use in marine applications. Influence of heat treatment on structure and phase structure of experimental alloys in the form of the sheets containing up to 0,15% of Sc and 0,25% of Zr is studied. The possibility of decrease in content of scandium more than twice is shown. The compositions containing up to 0,1% of Sc, providing a combination of high level of mechanical properties and corrosion resistance are offered. In particular, new materials on the level of strength properties are comparable to the industrial alloys containing about 0,25% of Sc and it is essential, more than twice exceed wrought alloys like 5083 type.

I-2: Corrosion of Al-Mg Alloys in Ethanol: Gustavo Kramer1; Estefanía Gauto1; Roberto Rozicki1; Claudia Méndez1; Alicia Ares1; 1IMAM (CONICET-UNaM)
    In the present research was performed the study of corrosion resistance of aluminum magnesium alloys, modifying the grain structures of the specimens and exposing them to ethanol solutions of both vegetal origin and commercial acquisition. Electrochemical tests for analysis were potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). From the results, it was found the relationship between the corrosion resistance and grain structure for these alloy / solution systems. Also, understand and propose corrosion mechanisms involved, compared with the various theories proposed by different authors.

I-3: Effect of Ni Addition on Microstructure and Tensile Properties of Squeeze Cast Aluminum Alloy A380: Li Fang1; Xuezhi Zhang1; Junxiang Zhou1; Henry Hu1; Xueyuan Nie1; Jimi Tjong2; 1University of Windsor; 2Ford Powertrain Engineering Research & Development Centre
    In this study, the influence of transition alloying element nickel to the mechanical properties of squeeze cast aluminum alloy A380 as one of the most common hypoeutectic Al-Si-Cu alloys used in the automotive industry was investigated. Nickel (Ni) addition varying from 0.5 up to 2. 0 wt. % was introduced into liquid A380. The alloyed melt was squeeze cast under an applied pressure of 90 MPa. The results of tensile testing on the Ni-containing A380 alloys show that Ni is an effective additive for improving their mechanical properties, in particularly, tensile strengths at room temperature. The as-cast microstructures of the squeeze cast conventional and Ni-containing alloys were observed by an optical microscope (OM) Examination of the analyzed microstructures indicate that the complex Ni-containing intermetallic phases forms once Ni is introduced. The presence of the Ni-containing intermetallic phases should be responsible to the improvement of mechanical properties. Based on the density measurements, it is found that the introduction of 2.0 wt% Ni into the A380 results in a trivial effect on its density by only 0.5%.

I-4: Creep Behavior of Cast Aluminum-Copper Alloys at 300° C: Brian Milligan1; Shibayan Roy2; Shane Hawkins2; Patrick Shower3; Amit Shyam2; 1Oak Ridge National Laboratory, Colorado School of Mines; 2Oak Ridge National Laboratory; 3Oak Ridge National Laboratory, Bresden Center for Interdisciplinary Research and Graduate Education
    As aluminum alloys are utilized at higher homologous temperatures, creep deformation becomes an important aspect of their mechanical behavior. The creep behavior of four Al-Cu alloys was studied at 300° C by measuring their steady state creep rate as a function of stress. The dominant creep mechanisms were identified for multiple stress regimes. For some alloys, diffusional creep was the dominant deformation mechanism at low stresses. The rate of diffusional creep deformation was dependent on grain size and the fraction of grain boundary area covered by precipitates. A modified version of the Coble creep model was developed to explain the observed diffusional creep behavior, and it provided a good fit to the experimental creep data. The fracture mode of the investigated alloys was dependent on the relative strength of the grain boundary region compared to the grain interior.

I-5: Warm Pressing of Al Powders: An Alternative Consolidation Approach: Peter Krizik1; Martin Balog1; Oto Bajana1; Maria Victoria Riglos2; Peter Švec Sr.1; 1Institute of Materials & Machine Mechanics SAS; 2Centro Atómico Bariloche
    This paper presents the warm pressing as an alternative PM approach to conventional press-and-sinter or hot working (e.g., extrusion, forging) consolidations of Al powders into complex near-net-shape parts of required mechanical properties. In this study gas-atomized Al powders (A1050 and A6061) of various particle sizes were consolidated by uniaxial pressing, with minimum plastic deformation induced, at temperatures of 22–430°C. The materials pressed ≤ 100°C showed poor strengths, ductility, Young`s modulus and electrical conductivity. The properties increased gradually when pressing temperature increased > 200 °C and reached values comparable to those of PM based and wrought materials. Similarly, the properties of the materials pressed < 200°C improved after annealing at 300°C for 2 h. This indicated formation of proper interfacial bonding between native oxide layers on adjacent Al powder particles (i.e., grains) > 200°C. With interfacial bonding established, fracture mechanism changed from brittle to ductile character.

I-6: Influence of Reinforcement Particle Size and Spatial Distribution on Microstructure and Mechanical Behavior of Precipitation Strengthened Al Matrix Composites: Chuandong Wu1; Kaka Ma1; Enrique Lavernia1; Guoqiang Luo2; Fei Chen2; Qiang Shen2; lianmeng Zhang2; 1UC Irvine; 2Wuhan University of Technology
    We report on an investigation of the influence of reinforcement particle size on microstructure and mechanical behavior of precipitation strengthened Al alloy matrix composites. Al 7075 alloy composites reinforced with B4C particles were selected as a model system in the present study. The bulk composites containing three types of B4C with different particle sizes were synthesized via plasma activated sintering and followed heat treatment. For a constant value of weight fraction of B4C, the composite with coarse reinforcement particles exhibited a relatively homogeneous and discrete distribution of the B4C particles while the composites with fine reinforcement exhibited agglomeration of the B4C particles. The composite with the smallest B4C particles possessed the highest yield strength and fracture strength. Moreover, quantitative analysis of the strengthening mechanisms and the fracture mechanism in the composites are discussed in details.

I-7: Hot Deformation Characteristics of Modified AA5052: Kwangtae Son1; Jiwoon Lee1; Shaekwang Kim2; Youngok Yoon2; Soongkeun Hyun1; 1Inha University; 2Korea Institute of Industrial Technology
    The main purpose of this study is to characterize the high temperature deformation behavior of modified 5052 Al alloy through hot torsion test. Specimens were hot-worked by torsion test at temperature range from 573 K to 773 K and at the strain rates of 0.1/s - 10/s. Temperature rise during plastic deformation due to deformation heat was considered and the compensated flow curves were derived to estimate the hot deformation behavior of experimental Al alloy. Peak stress had a tendency to have large value on the condition of lower temperature and higher strain rate, which was an opposite result in comparison of effective strain. Obtained processing map of the experimental alloy noticed that the maximum power dissipation values were observed at 773K of minimum and maximum strain rate. Microstructure investigation was carried out to interpret the acquired result of processing map.

I-8: Study on the Anodic Oxide Film Formation on Die Casting Aluminum Alloy: Juseok Kim1; Jongmoon Park1; Sungmo Moon2; Minsu Park3; Nojin Park1; Myunghoon Oh1; 1Kumoh Institute of Technology; 2Korea Institute of Material Science; 3Jangwontech. CO.LTD
    Formations of anodic oxide films on Al alloys are crucially dependent on composition of alloying element. Si in die-casting alloy can’t contribute to the oxygen gas evolution and dissolution, and Si particles present in die-casting alloy decrease the area where anodic oxide film can grow. Growth of anodic oxide films on die casting Al is non-uniform because of Si particles. In this work, in order to understand the anodic oxide film growth behavior of die-casting Al alloy, Al1050 alloy and aluminum die-casting alloy for smartphone case were anodized at constant voltage and current density conditions in acidic and alkaline solutions. The behavior of formation voltages of Al1050 and die-casting alloy were recorded with treatment time, and the film thickness, surface roughness were measured. The presence of Si particles in Al alloy appeared to increase the film formation voltage and induced non-uniform thickness of oxide films with a lot of cracks.

I-9: Mechanical Properties of Miniature Samples of Additive Manufactured Aluminum: An Experimental and Computational Study: Matan Tubul1; Tsahi Safar1; Shai Amar1; Ziv Ungarish1; Eitan Tiferet1; Itzhak Orion2; Eytan Kochavi2; 1NRCN; 2Ben-Gurion University of the Negev
    The Small Punch Test (SPT) is a mechanical testing method in which a foil is bended to failure using a ball punch, while the force-displacement curve is recorded. This curve is used to obtain the mechanical properties of the tested material. This method is often used to obtain the properties of irradiated materials that are available only as miniature samples. In the current study, disc samples with a diameter of 3mm and thickness of up to 260µm were tested. Standard aluminum alloys were used to investigate the effects of various test parameters on the obtained results. A verified and validated numerical finite element model (FEM) of the testing device was developed. The SPT and FEM were used to investigate the mechanical properties and the unique microstructure of additive manufactured (AM) aluminum. The applicability of SPT and its ability to obtain the mechanical properties for AM materials will be discussed.

I-10: Modification of Intermetallic Compounds in Aluminum Alloys by Using Ultrasonic Vibrations: Tomohiro Ishii1; Sergey Komarov1; 1Tohoku University
    Although effects of ultrasonic vibrations on aluminum alloy structure have been the subject of many studies, there is still conflicting data regarding influence of ultrasonic on intermetallic compounds. The available literature reveals that ultrasonic can cause both their refinement and coarsening. This study examines combined effects of ultrasonic cavitation, acoustic streaming and temperature on behaviour of various intermetallic compounds. In experiments, 1 kg of aluminum alloy was melted, and then ultrasonic vibrations were introduced into the melt within a certain temperature range for fixed time. Then, the melt was poured into various moulds to provide well-controlled cooling and solidifying conditions. Intermetallic compounds were characterized for their chemical composition, morphology, size and mechanical properties. Water model experiments and numerical simulation were performed to elucidate the behaviour of intermetallic compounds in the melt. The ultrasonic effects are discussed with emphasis on heat and mass transfer during nucleation and growth of intermetallic compounds.

I-11: Structure and Microhardness Analysis in Samples Directionally Solidified: Alex Kociubczyk1; Roberto Rozicki1; Gustavo Kramer1; Alicia Ares2; 1IMAM (CONICET-UNaM); 2CONICET/FCEQyN-UNaM
    The columnar–to-equiaxed transition (CET) was observed in unidirectionally solidified Al-10%Si and Al-10%-2.5%Cu (pct wt) alloys from the chill face. The transition occurs when the gradient in the melt ahead of the columnar dendrites and the columnar growth velocities reach critical values. Considering the characteristics of alloys and the temperature profiles at the interphase of solidification, the microstructure obtained is analyzed (primary, secondary and tertiary dendritic spacings). Furthermore, variations in microhardness as a function of concentration and as a function of both sample length and width are reported.

I-12: Fatigue and Tensile Properties of Hypoeutectic Al-Si-Mg Alloys with Excess Mg Contents: Young-Ok Yoon1; Su-Yeon Lee1; Seong-Ho Ha1; Bong-Hwan Kim1; Hyun-Kyu Lim1; Shae K. Kim1; 1Korea Institute of Industrial Technology
    Hypoeutectic Al-Si-Mg casting alloys are widely used in the automotive and aerospace industries as structural components due to an excellent combination of castability and mechanical properties. Mg addition into Al-Si alloys leads to significant age-hardening behavior through Mg2Si precipitates, and offers improved strength. Typical Al-Si-Mg casting alloys have limited Mg contents of about 0.3 mass% and the maximum value of 0.7 mass% in the case of A357 alloy. However, most of the work on hypoeutectic Al-Si alloys containing Mg are limited to 0.6wt%. In the present study, fatigue and tensile properties of Al-Si-Mg alloys Mg-enriched up to 0.8 mass% were investigated. Mg+Al2Ca master alloy as an alloying element of Mg was employed for the eutectic Si modification, control of Mg loss and entrainment of Mg-based oxide inclusion occurred during melting process.

I-13: Microstructure and Mechanical Properties of Al Alloys with Mn and AlTiB Addition: Hyo-Sang Yoo1; Yong-Ho Kim1; Chang-Gi Jung1; Seong-Hee Lee2; Hyeon-Taek Son1; 1Korea Institute of Industrial Technology; 2Mokpo National University
    Aluminum alloys have attracted significant interest due to their high potentially lightweight materials for corrosion resistance, specific strength, reasonable formability and recycling efficiency. Also, the strength and corrosion resistance of aluminum alloys can be improved by alloying element addition and thermo-mechanical treatment process, which allow aluminum alloys to have optimum grain structure suitable for various applications. In the present work, the effect of AlTiB and Mn addition on the microstructure and tensile properties of Aluminum alloys. The Aluminum alloy melt was held at 800℃ and then poured into a mould at 200℃. Aluminum alloys were hot-extruded into a rod that was 12mm in thickness with a reduction ratio of 40:1. The microstructure of specimens was examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), optical microscopy (OM). The mechanical properties of the Aluminum alloys were maintained by a tensile test.

I-14: Mechanical Properties of Near Surface Microstructures (NSM) of Hot Rolled and Cold Rolled 5xxx Aluminum Alloys: Sepideh Parvinian1; 1Georgia Institute of Technology
    Near surface deformed layers which are formed during hot and cold rolling processes of Aluminum alloys exhibit unique microstructures compared to that of the bulk layers. High shear strain during rolling is responsible for the formation of non-uniform Near Surface Microstructures (NSMs) consisting of ultrafine nano-grains in the outmost deformed layer. The subsurface layer of thickness of approximately 1.5–8 µm characterized by mainly elongated grains serves as a transition region between the near surface and the bulk layers. Due to strain gradient distribution of shear strain induced by rolling, the microstructures become highly heterogeneous. To better assess the micromechanical properties of these thin near surface layers in Al alloys, nanoindentation was implemented on top surface as well as cross section of rolled alloys containing near surface microstructures. Samples were characterized by SEM and Atomic Probe Microscopy. The surface topography of samples displaying their roughness values were obtained as well.

I-15: Friction Stir Welding of Wrought and Cast Aluminum Alloys: Heat Transfer Modeling and Process Optimization: Yi Pan1; Diana Lados1; Xiangbin Wang1; 1Worcester Polytechnic Institute, Integrative Materials Design Center
    Friction stir welding (FSW) is a relatively new solid-state joining technique, which provides good weld properties and behavior, even without the need of post-weld heat treatment. Understanding and predicting microstructure evolution and mechanical properties in FSW is critical for high-integrity structural design and material-process optimization. Four aluminum alloys (wrought 6061 and cast A356, 319, and A390) have been investigated in both as-fabricated and pre-weld heat treated conditions using various combinations of rotation and traverse speeds. An original thermo-mechanical model was created to predict the thermal history, stress distributions, deformation rates, and velocity fields in FSW. Further, a methodology for evaluating and indexing weld quality was also developed and used to establish optimized processing domains for each material. Resulting microstructures, hardness/micro-hardness, and tensile properties were systematically evaluated and mechanistically correlated to morphological changes in grain structures, characteristic phases, and strengthening precipitates using both experimental characterization and thermo-mechanical model predictions.

I-16: Friction Welding Process Between 6351-T6 Aluminum Alloy And 1020 Steel: Sheron Tavares1; Alexandre Bracarense1; 1Federal University of Minas Gerais
    In the transportation industry the need for lighter fabrication materials, has strongly attract the interest in joining dissimilar materials, for example, steel with aluminum. These materials have very different thermal and mechanical properties, and when welded by fusion processes, the formation of intermetallics which embrittle the weld occurs. This study aimed to investigate the mechanical and metallurgical properties of butt joints welded by conventional friction process. Aluminum and steel bars with 12.7 mm diameter were welded using a drill bench, applying different process parameters. The characterization of the interface was performed by optical microscopy (OM), scanning electron microscopy (SEM) and chemical analysis by energy dispersive X-ray (EDS). The mechanical strength of the joint was measured by the Vickers microhardness testing and tensile testing.

I-17: Quantifying Beta Phase Precipitation Rate in Marine Grade 5xxx Alloys: William Golumbfskie1; Jennifer Gaies1; Emily Holcombe1; Dan Scotto D'Antuono2; Mitra Taheri2; 1Naval Surface Warfare Center, Carderock Division; 2Drexel University
    5xxx aluminum alloys are used in marine applications due to their corrosion resistance coupled with high as-welded strength. A particular concern is that 5xxx alloys can become sensitized in service, ultimately leading to stress corrosion cracking (SCC). Sensitization occurs when magnesium precipitates out of solution forming a deleterious beta-phase (Mg2Al3) continuously around grain boundaries. Results have shown a significant variation in the sensitization rate for different lots of 5083 H116 plate. This investigation will quantify the effects of processing and resultant microstructure on the rate of beta-phase precipitation and will be compared to a new sensitization resistant temper. The microstructure and degree of sensitization will be characterized using microscopy coupled electron backscatter diffraction (EBSD) and the ASTM G67 test. The results of this investigation will aid in filling the knowledge gap to accurately predict sensitization rates for marine grade aluminum alloys.

I-18: Effect of Different Temperature Sintered SiC Particles on Microstructure and Mechanical Properties of SiC Reinforced Aluminum Matrix Composites: Bo Zhang1; Menghan Ao1; Long Wang1; Kailin Long1; Jienan Liu2; Guangxin Wu3; 1Guiyang Industrial Technology Institute; 2Guiyang Vocational and Technical College; 3Shanghai University
    The effects of SiC particles under different sintering temperature on microstructures and properties of 10% (volume fraction) SiCp/ZL109Al composites were investigated in this paper. After 5 hours oxidation sintering, SiC particles were added into molten aluminum. By use of stirring casting method, an aluminum matrix composite was prepared. The thickness of SiC oxidation layer increased with increasing the sintering temperature from 800℃ to 1100℃. TEM observation revealed that the oxidation layer formed in 900℃. When temperature increased higher than 1000℃, SiC Particles are completely covered by oxidized layer. The thickness of oxidation layer was 0.096-0.5425um with sintering temperature from 800℃ to 1000℃. The density and friction coefficient of composite would be the best under the condition of sintering temperature was 1000℃. At that time the oxidation layer was 0.383um and MgAl2O4 phase generated instead of Al4C3 on the layer which would enhance combination strength of composite with stronger matrix interface.