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Full-Text Articles in Mechanical Engineering
Fatigue Performance Improvement By Dynamic Strain Aging And Dynamic Precipitation In Warm Laser Shock Peening Of Aisi 4140 Steel, Chang Ye, Gary Cheng
Fatigue Performance Improvement By Dynamic Strain Aging And Dynamic Precipitation In Warm Laser Shock Peening Of Aisi 4140 Steel, Chang Ye, Gary Cheng
Dr. Chang Ye
Warm laser shock peening (WLSP) integrates the advantages of laser shock peening and thermal-mechanical treatment (TMT) to improve material fatigue performance. Compared to traditional laser shock peening (LSP), warm laser shock peening, i.e. LSP at elevated temperature, leads to better performance in many aspects. WLSP can induce nanoscale precipitations by dynamic precipitation and high density dislocation by dynamic strain aging (DSA), resulting in higher surface strength, which is beneficial for fatigue life improvement. Due to pinning of dislocation structure by nanoscale precipitates, and the pinning of dislocation structure by Cottrell atmosphere, or the DSA effect, stability of the dislocation arrangement …
Mechanism Of Fatigue Performance Enhancement In A Superhard Nanoparticles Integrated Nanocomposites By A Hybrid Manufacturing Technique, Dong Lin, Chang Ye, Yiliang Liao, C. Liu, Gary Cheng
Mechanism Of Fatigue Performance Enhancement In A Superhard Nanoparticles Integrated Nanocomposites By A Hybrid Manufacturing Technique, Dong Lin, Chang Ye, Yiliang Liao, C. Liu, Gary Cheng
Dr. Chang Ye
A hybrid manufacturing process, which contains Laser Sintering (LS) and Laser shock peening (LSP), is introduced to generate iron-TiN nanoparticle nanocomposites. It is a two-step process including LS followed with LSP. Before LS, TiN nanoparticles mixed with iron powders are coated on samples surface. After LS, TiN nanoparticles are embedded into iron matrix to strengthen materials. Then LSP is performed to introduce work hardening and compressive residual stress. The existed nanoparticles increase the dislocation density and also help to pin the dislocation movement. Better residual stress stability under thermal annealing can be obtained by better dislocation movement stabilization, which is …