Environmentally Assisted Cracking: Theory and Practice: Poster Session
Sponsored by: TMS Structural Materials Division, TMS: Corrosion and Environmental Effects Committee
Program Organizers: Bai Cui, University of Nebraska Lincoln; Raul Rebak, GE Global Research; Srujan Rokkam, Advanced Cooling Technologies, Inc.; Jenifer Locke, Ohio State University

Tuesday 5:30 PM
March 16, 2021
Room: RM 18
Location: TMS2021 Virtual

Session Chair: Srujan Rokkam, Advanced Cooling Technologies


Extraction of Zinc from Zinc Hypoxide in the Process of Ammonia Leaching: Linfei Zhao1; Hui Li1; Jinglong Liang1; 1North China University of Science and Technology
    Zinc hypoxide belongs to the secondary resources of the lead, zinc and steel industries, the recovery of valuable metals in zinc hypoxide is of great significance for energy conservation and environmental protection. In this study, NH3-NH3HCO3-H2O leaching system was used to recover metal zinc in zinc hypoxide. The dissolution equilibrium analysis of the leaching shows that zinc in this system exists in the form of zinc-ammonia complex in solution, and the dominant form is [Zn(NH3)4]2+. Orthogonal test result indicates that the most influential factor for zinc leaching rate is nT(NH3)/n(Zn), followed by solid-liquid ratio and leaching time, and [NH4]/[NH3]T has little effect on it. Under the optimum experimental conditions using nT(NH3)/n(Zn)=5:1, [NH4]/[NH3]T=1.2:4, temperature of 30C, leaching time of 30min, liquid/solid ratio of 7mL/g, the leaching rate of zinc can reach up to 79.94%.

The Impact of Laser Shock Peening Parameters on the Ability to Mitigate Stress Corrosion Cracking in Al-Mg Alloys: Eric Dau1; William Golumbfskie2; Matthew McMahon2; 1Vision Point Systems; 2Naval Surface Warfare Center, Carderock Division
    Laser shock peening is a technology that has variable ability to impart compressive residual stresses into a material to mitigate stress concentration formation and, potentially, propagation of phenomena such as fatigue and/or stress corrosion cracking. This effect is achieved through bombardment of a water layer on the alloy surface with a laser, which creates plasma as well as a shock wave that travels into the underlying Al-Mg material to deform it to a limited depth. In the current work, we evaluate a range of laser shock peening parameters to determine how well this treatment may be tuned towards mitigating stress corrosion cracking in Al-Mg alloys. These evaluations are carried out in near worst-case crack growth scenarios on specimens of varying sensitization, with the power density and overlap parameters of the LSP processing adjusted to evaluate optimum combinations and treatment efficiency for the intended goal.