Material competition in the auto industry has traditionally been intensive. Steel has been the dominant material used in automobiles since the 1920s, but requirements for cleaner vehicles are forcing automakers to reduce exhaust emissions. One solution that has attracted interest in the last decade is replacing steel automotive parts with equivalent magnesium (Mg) parts to lower total vehicle weight. At the moment, Mg automotive parts are only manufactured by casting and extrusion, and Mg alloys have not yet been used or constructed into sheets for automotive body parts. Current research at the FATSLab aims to determine the feasibility of using these alloys for such applications.
Resistance spot welding (RSW) is the most common joining process in automotive bodies; a typical vehicle in North America contains about 4000 to 5000 spot welds. However, RSW for wrought Mg alloys has not yet been studied to determine its applicability. Since spot welds are points of stress concentration, they are more likely to fail due to fatigue than other areas. Therefore, verified fatigue models are needed to make sure that spot-welded components will perform satisfactorily throughout the total life of vehicles.
Sample Publications and Conferences
Behravesh B., Jahed H., Lambert S., Chengji M, "Constitutive Modeling for Cyclic Behavior of AZ31B Magnesium Alloy and its Application," Advanced Materials Research Vols. 891-892 (2014) pp 809-814;
Behravesh B, Jahed H, Lambert S, "Fatigue characterization and modeling of AZ31B magnesium alloy spot-welds," International Journal of Fatigue 64 (2014) 1–13;
Behravesh S. B., Jahed H., and Lambert S., "Characterization of magnesium spot welds under tensile and cyclic loadings," Materials & Design 32(2011), pp. 4890-4900.
Behravesh SB, Jahed H, Lambert S, "Cyclic Plasticity Constitutive Modelling of AZ31B," International Symposium of Plasticity, Freeport, Bahamas, Jan 2014;
Behravesh SB, Jahed H, Lambert S, "Fatigue Characterization and Modeling of AZ31B Spot-welded Joints, ASME 2013 International Mechanical Engineering Congress & Exposition,"IMECE2013, San Diego, California, November, 2013;
Behravesh SB, Jahed H, Lambert S, "Fatigue Characterization and Modeling of AZ31B Spot-welded Joints," ICMFF10, Kyoto, Japan, 3-7 June 2013;
Badarinarayan H., Behravesh S. B., Jahed H., Lambert S., et al., "Monotonic and Fatigue Behavior of Mg Alloy Friction Stir Spot Welds: An International Benchmark Test in the “Magnesium Front End Research and Development” Project," TMS 2011 Annual Meeting & Exhibition2011: San Diego, California.
Behravesh B., Liu L., Jahed H., Lambert S., Glinka G., Zhou Y. , "Effect of Nugget Size on Tensile and Fatigue Strength of Spot Welded AZ31 Magnesium Alloy," Detroit, MI, April 13-15, 2010.