Effect of Steel shot peening Time on some Mechanical Properties of Friction stir Welds for Aluminum Alloy (2024 – T3)

The aim of this work is to study the effect of the time of shot peening 3mm diameter steel balls on the mechanical properties of (2024 - T3) aluminum alloy butt welds. The welds were joined using Friction stir welding method. Mechanical tests) Tensile strength, hardness, fatigue strength( were performed on welded joints to determine the variation of these properties. The experimental results of SP time, 5 and 10 minutes give an improvement in mechanical properties. It was found that the longer the time of shot peening the mechanical properties are increased to a certain extent than the effect begins whereas when shot peening time at 15 min the mechanical properties decrease due to the concentration of stresses and surface annealing. Results show that the best mechanical properties of the welded zone were obtained at 10 minutes shot time due to the high compressive stresses generated by shot peening.

Pulsed-light surface annealing for low contact resistance interfaces between metal electrodes and bismuth telluride thermoelectric materials

The pulsed light annealing process improves the efficiency of bismuth telluride based thermoelectric devices by reducing the contact resistance significantly.