Experimental and Numerical Study of Needle Peening Effects on Aluminum Alloy 2024-T3 Sheets

Author:  Hongyan Miao, Julio Méndez, Sylvain Forgues, Martin Lévesque
Source:  ICSP-13
Doc ID:  2017132
Year of Publication:  2017
Introduction: Shockform Aeronautique Inc. is a Quebec based pioneer in peening equipment solutions for repairs of high-value components in the aerospace and defense industries. Shockform is currently developing a portable needle peening tool called the SPIKER® for peen forming and local repairs. These developments aim to establish needle peening as a viable alternative to manual shot peening and rotary flapper peening for niche applications. Needle peening uses relatively hard spikes, called needles, powered by a pneumatic source in order to hit the surface of a ductile workpiece. As the powered tool is pressed against and moved along the component's surface, the impacting needles stretch the impacted surface, creating indentations as seen in Figure 1(a). The bulk of the substrate surrounding the deformed material opposes this stretching, therefore creating a region of compressive stresses, as seen in Figure 1(b). The near-surface compressive layer of the deformed material hinders crack propagation under cyclic loading and therefore increases the material's fatigue life. Needle peening results in a clean procedure that does not require media collection systems. This process is suitable for manufacturing environments where Foreign Object Damage (FOD) and personnel health and safety would be compromised by using a non-captive peening technology. The absence of consumable material also makes it optimal for local repairs and constitutes therefore a highly practical portable repair equipment. Needle peening has a high adoption potential because of its portable design and operational features that target niche overhaul needs currently not covered by current peening equipment.

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