TWI

An experimental investigation was undertaken into the preparation and mechanical properties of two candidate substitutes to MP 159 Ni-Co alloy as tool materials for friction stir welding of high strength aluminium alloys. The alloys studied were "Aerex 350" (Ni, 25%Co, 16.9%Cr, 3.9%Ta, 2.9%Mo) and ausformed H13 tool steel (fabricated from annealed H13 tool steel by thermomechanical processing). Mechanical tests were conducted at 482 deg.C to characterise smooth bar mechanical properties (room temperature and 482 deg.C), notched tensile strength, strain hardening coefficient, notch sensitivity, strain rate sensitivity and notched rotating bending fatigue. Issues discussed include the isothermal transformation and TTT diagrams for H13 tool steel, the ausforming procedure, and a fatigue life comparison of the different alloys.

11th International Symposium, 17-19 May 2016, Session 8B: FSW, Paper 04