It was conducted on Tuesday, 31/10/2023, in Dr. Mahdi Hantoush Hall the discussion of the master’s thesis of the student Safi Ramzi Safi, which is tagged:
” Strength Improvement of Spot-Welding Joint for Commercial Aluminum Sheets by Adding Metallic Powder “.
The discussion committee consisted of names listed below:
1- Prof. Dr. Mohammad Qasim Abdullah (Chairman)
2- Prof. Dr. Sabah Khammass Hussein (Member)
3- Asst. Prof. Dr. Suhair G. Hussein (Member)
4- Prof. Dr. Moneer Hameed Toliphih (Supervisor)
5- Prof. Dr. Muhsin Jaber Jweeg (Supervisor)
The aim of this study includes the improvement of RSW in commercial aluminum, responding to the demand for aluminium within the automotive sector by the investigation into the integration of two distinct metallic powder, AA7049 and AA2024, in varying compositions at the faying surface between commercial aluminium AA1050 sheets to enhance RSW strength. The study begins with finding the best welding conditions for resistance spot welding (RSW) to weld AA1050 sheets at normal condition (without powder) using a low-power supply welding machine to achieve maximum tensile shear strength of the joint for two distinct sheet thicknesses, 1 mm and 2 mm. The improvement stage starts with forming different sizes of cavity in the lower sheet to investigate the effect of amount of added powder. Then weld the sheets at the best welding conditions obtained in the first stage. The tensile shear force test was performed to evaluate the strength of the weldments for all stages. Accordingly, best welding conditions conforming to a 14.85 kA welding current and 0.79 kN electrode force for both thicknesses, coupled with 2 cycles and 12 cycles of welding time for 1 mm and 2 mm thicknesses, respectively, yielding remarkable tensile strengths of 250 N and 225 N for 1 mm and 2 mm thicknesses, similarly. The addition experimentally investigates the influence of powder amounts on weld strength and morphology. Mechanical investigation shows substantial advancements, especially when a high proportion of the copper and Zinc elements in the composition is exercised. The tensile shear force endured remarkable improvement, enhancing by 66.6% and 51.1% with the AA2024 and AA7049 powders at cavity depth 0.3 mm and 0.4 mm, respectively. The study identifies the optimal powder amounts, spotlighting the amplified hardness of the nuggets formed by the additive powder in discrepancy to normal welds.
After the scientific discussion by the members of the discussion committee, the researcher received a rating of (very good).
