Thread-stripping test procedures leading to factors of safety data for friction-drilled holes in thin-section aluminium alloy

Friction drilling is a hole-making process suitable for thin sections of ductile metal. A rotating tool plunged into the workpiece to form pilot hole. The hole then threaded in follow-up process. bushing forms on exit side hole, which allows longer engagement lengths assemblies. For comparison purposes, four combinations threaded-hole processes were applied 1.5 mm-section, 6082-T6 aluminium alloy. involved friction and twist followed by thread forming or cutting. Vickers hardness microstructural analyses used assess condition material. An in-house test method was developed measure axial load–deflection response. Progressive failure occurred stripping. gave peak loads 35% higher than conventionally drilled tapped holes. Also, increased from 111HV parent metal 125HV (with an increase depths 0.5 mm) due work hardening. Evidence precipitate dissolution negligible suggests that operated below solvus temperature. novel approach determining reliably-based, thread-stripping Factors Safety ( FoS ) presented. range 3.61 4.38 reliability 95% 99.9% against stripping friction-drilled, formed joints. • Bespoke procedures thin-walled alloys. Detailed analysis alloy 6082-T6. Benchmark comparisons subtractive processes. Microstructure linked with mechanical performance friction-drilled New selection design factors avoidance striping.