Influence of Pre-Solidified Grains (PSG) on the Performance of (Al, Zn, Mg)-Fe Dilute Eutectic Aluminum Alloy Castings

Tuesday, October 1, 2024: 9:00 AM
25 A (Huntington Convention Center)
Mr. Talha Aziz, M.A.Sc. , McMaster University, Hamilton, ON, Canada
Dr. Kumar Sadayappan, Ph.D. , CanmetMATERIALS, Hamilton, ON, Canada
Dr. Andre Phillion , McMaster University, Hamilton, ON, Canada
Dr. Xiaochun Zeng , McMaster University, Hamilton, ON, Canada
Mr. Gabriel Birsan , CanmetMATERIALS, Hamilton, ON, Canada
Dr. Glenn Byczinski , Nemak USA/CAN, Windsor, ON, Canada
Dr. Anthony Lombardi , Nemak USA/CAN, Windsor, ON, Canada
Dr. sumanth shankar , McMaster University, Hamilton, ON, Canada
Targets of net-zero by many countries have triggered a global shift in many industries to implement environmentally conscious industrial practices and reduce carbon emissions. In the automotive industry specifically, the rise of electrification and promotion of vehicles such as battery electric vehicles (BEVs) have necessitated the exploration of substitutions to existing advanced high-strength steels (AHSS) that are predominantly used for structural components to reduce the total vehicle curb weight. As such, material alternatives that present lightweighting capabilities while maintaining high strength-to-weight ratios are demanded for structural applications. A new family of (Al, Zn, Mg)-Fe dilute eutectic casting aluminum (DECA) alloys, named Nemalloy HE700 (Al-4.7Zn-0.95Mg)-1.1Fe-0.05Ti (all in w%), with Zn and Mg for precipitation strengthening and Ti-B for grain refinement, was developed for automotive structural castings. The DECA alloy presents a uniquely beneficial mode of solidification wherein the two solidifying phases of primary Al and Al13Fe4 evolve together as collaborative growth to significantly reduce the size and increase the distribution of the shrinkage within the boundaries of the two eutectic phases; thus, improving the properties and performance over conventional AlSiMg die casting alloys. Entrapped gas porosity and pre-solidified grains (PSG) or externally solidified grains (ESC) are the critical defects in these structural castings affecting the properties and performance of the component. The HPDC process parameters such as shot delay intervals were varied to deliberately change the PSG content in the casting study the effects on the casting quality and uniaxial tensile properties. Quantitative metallography, uniaxial tensile and bend tests were performed to understand and determine the influence/effects of both the entrapped porosity and PSG in HPDC structural Al components of the HE700 DECA alloy.
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See more of: Light Metal Technology