科研之友
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摘要
The thermal cycling in the coaxial laser cladding process can cause significant variations in the strength of cladded parts as well as the development of residual stresses, large distortions, and even cracking. In the current study, the hardness variations, induced residual stress distribution, and the developed distortion characteristics of cladded parts are examined for different deposition tool paths. The research is conducted by means of numerical simulations validated by experimental results for selected surface cladding deposition strategies. The specimens were made using P420 stainless steel powder clad onto an AISI 1918 substrate. In the previous studies by the authors, it was found that the transient thermal solution using a moving heat source simulation technique required several days of computational time for small cladded parts, making it impractical for industrial applications. In the present research work, a modeling approach using a steady-state thermal solution was proposed. This technique produced similar results for hardness and residual stress in a shorter time period, but the resulted distortion values were not accurate. Consequently, a thermo-mechanical modeling approach was adopted that provided virtual distortion solutions correlating well with the experimental results. These models were subsequently employed to explore various process planning scenarios. The effect of surface cladding deposition patterns, the substrate dimensions, the plate dimension's aspect ratio, and the time gap between beads deposition were simulated and the strength and physical defects of the clad layer results are compared. Moreover, the mechanical response and properties for a full-scale gasket part is investigated as an example representing an industrial application.
- 出版日期2018-6
