Effect of pin shape on interfacial microstructure and joint strength in friction stir lap welding with a retained viscous layer

Key Points

• Enhanced joint strength observed with specific pin shapes, significantly influencing performance outcomes.
• Joint strength increased by 25% when using a novel pin shape in friction stir welding processes.
• Observational analysis using various pin shapes in friction stir lap welding to assess microstructural changes.
• Findings suggest optimized pin designs may lead to better welding efficiencies and material properties.