Near surface transformations of stainless steel cold spray and laser cladding deposits after turning and ball-burnishing

[摘要] An experimental study is performed to assess the surface integrity of cold sprayed and laser cladded 17-4PH stainless steel deposits after turning and ball-burnishing. A special emphasis is given to near surface microstructure and residual stress distribution. It is shown that both cold spray and cladding deposits could be machined under cutting conditions close to those employed for a conventionally rolled 17-4PH stainless steel. Analysing the resulting microstructure in the near-surface revealed that the turning and ball-burnishing processes affect the coating surface and generate a thin layer where the microstructure can be hardly identified. Residual stress measurements by an X-ray diffraction method revealed that turning results in tensile residual stresses in the near-surface of both the cold spray and laser cladding deposits. Surface treatment by ball-burnishing can be significantly beneficial as compressive residual stresses were measured in both coatings in the near surface zone but to a larger extent in the Madded material. The comparison of the two profiles showed that the cutting and deformation mechanisms can be significantly different depending on the intrinsic nature of the deposited microstructure.

[发布日期] 2019-08-15

[效力级别]  Proceedings Paper

[关键词] Cold spray;Laser cladding;Surface integrity;Microstructure;Residual stresses