12th International Conference on Magnesium Alloys and their Applications (Mg 2021): Wrought Alloys II
Program Organizers: Alan Luo, Ohio State University; Mihriban Pekguleryuz, McGill University; Sean Agnew, University of Virginia; John Allison, University of Michigan; Karl Kainer; Eric Nyberg, Kaiser Aluminum Trentwood; Warren Poole, University of British Columbia; Kumar Sadayappan, CanmetMATERIALS; Bruce Williams, Canmetmaterials Natural Resources Canada; Stephen Yue, Mcgill University
Tuesday 10:50 AM
June 15, 2021
Room: Contributed II
Location: Virtual
Session Chair: Hamid Jahed, University of Waterloo
Effect of Deformation Temperature on Microstructure and Texture Evolution in Cast AZ80 Magnesium Alloy: Paresh Prakash1; Mary Wells1; Bruce Williams2; 1University of Waterloo; 2CanmetMATERIALS, Natural Resources Canada
This research studies the effect of deformation temperature on the microstructure and texture development in a cast AZ80 magnesium alloy within 300°C-400°C. The thermodynamic-stability of the Mg17Al12 phase greatly decreased with an increase in the deformation temperature. The precipitates were present in multiple morphologies in the material deformed at 300°C, while the different precipitate morphologies affected the occurrence of DRX in the material differently. Mg17Al12 precipitates in the lamellar morphology are suggested to have promoted DRX and texture randomization, while in the lath morphology restricted the occurrence of DRX. Mg17Al12 precipitates were not present in the material deformed at 400°C, while the DRX took place by the grain boundary bulging mechanism, and the DRXed grains preserved the deformation texture. The results indicate that the effect of deformation temperature on the microstructure and texture evolution is especially pronounced for this alloy owing to the changing thermal-stability of the Mg17Al12 precipitates.
Fatigue Characterization and Modelling of Forged AZ80 and ZK60 Magnesium: Andrew Gryguc1; Seyed Behzad Behravesh1; Hamid Jahed1; Mary Wells1; Bruce Williams2; Xuming Su3; 1University of Waterloo; 2CanmetMATERIALS; 3Ford Motor Company
The mechanical and fatigue properties of two commercially available Mg alloys (AZ80/ZK60) were investigated following a comprehensive forging development process to produce near-net-shape structural components. Characterization of the tension/compression and shear responses were done for a variety of different forging conditions to understand the structure-property relationship and optimize the key forging process parameters. The multiaxial fatigue response of the forged alloys were characterized, including the effects of phase angle and proportionality of the loading. The effects of the materials yield asymmetry and anisotropy in its cyclic behaviour was investigated in detail and phenomenologically linked to damage mechanisms. Strain, stress and variable amplitude fatigue experiments were carried out and energy based predictive models proved to provide a reliable life prediction for the forged Mg alloys. Full scale forging was successfully completed for both alloys producing defect free components with favourable properties that achieved a mass savings of 37% over the baseline.
Understanding Deformation Behaviour of AM50 AND AZ31 Magnesium Extrusions with Various Heat Treatments in Comparison with AA6063 and AA6082 Aluminum Extrusions: Baris Kara1; Asım Zeybek1; Enes Kurtulus1; Hakan Aydin2; Meryem Atalay2; 1Yesilova Holding; 2Uludag University
The effect of the cooling methods after extrusion and subsequent heat treatment on mechanical properties of AM50 and AZ31 were studied. For each alloy, the influence of orientation of the specimen with respect to the extrusion direction was also investigated in comparison with 6063 and 6082 aluminum extrusions. The results obtained by hardness tests and charpy impact tests demonstrate that heat treatments have no significant effect on hardness and fracture energy values of AZ31 and AM50 alloys. Tensile test results also generally support this statement except that supersaturated solid solution (solution heat treatment followed by quenching in water) AZ31 plate shows significant loss in yield strength, but increase in elongation. However, the fracture energy obtained by charpy impact test and its tensile strength are similar to those under the different heat treatment conditions. AZ31 and AM50 extrusions exhibit highly anisotropic behaviour especially in terms of elongation values. AA6063 and AA6082 aluminum extrusions display low anisotrophy and provide high fracture energy values corresponding to their elongation values. However, AM50 and AZ31 alloys provide low fracture energy values regardless of their elongation values.
Investigation of the Effect of Extrusion Speed on Mechanical and Micro-structural Characteristics in a Tubular Profile Extruded from AM50 Magnesium Alloy: Enes Kurtulus1; İrem Sapmaz1; Emrah Fahri Özdoğru2; 1Yesilova Holding; 2TRI Metallurgical Company
During the extrusion process of magnesium alloys, the extrusion speed has different effects on the microstructure and mechanical properties of the material. In this study; tubular extruded profiles produced from AM50 magnesium alloy were investigated. Extrusion production was carried out with 1 mm / s, 1.5 mm / s and 2mm / s ram speed, respectively. Tensile tests were carried out on the tensile test samples taken in the extrusion direction. As a result of these tests, yield strength, tensile strength and elongation values were achieved for different extrusion speeds were obtained and compared with each other. In addition, microstructure investigation was carried out including particle sizes and hardness measurements on tensile test samples via both optical and SEM analysis techniques. Finally; the fracture surfaces of the samples were examined by the SEM method and the differences were examined.
Aging Kinetics within GP-zone Forming, Dilute, Quaternary Alloys Containing Ca: Oluwaniyi Ajiteru1; Sean Agnew1; 1University of Virginia
Quaternary alloy systems Mg-Al-Ca-Mn (AXM) and Mg-Zn-Zr-Ca (ZKX) have emerged as promising candidates for application due to an attractive combination of properties, including good ductility and moderate strength as well as high extrusion limits. In order to achieve this good balance of properties, the alloys rely upon the formation of a dense population of ordered, Guinier-Preston (GP) zones which contain Al and Ca (AXM) or Zn and Ca (ZKX), respectively. It has already been shown that they exhibit attractive aging characteristics, such as a short aging times to obtain the peak-aged condition, and this has made them attractive for paint bake-hardening. In the present study, the focus is on over-aging. Samples are aged over a range of temperatures with the goal of determining if these alloys are vulnerable to “natural over-aging,” that is over-aging at ambient temperatures, within a time frame that could jeopardize their usefulness in application.