会议专题

NUMERICAL AND EXPERIMENTAL INVESTIGATION OF THERMAL STRESSES AND DISTORTIONS IN THE INDUCTION ASSISTED LASER CLADDING

In the laser cladding process the powdery coating material is absorbed by the laser induced melt pool yielding a strong joint between coating and substrate. The very high gradients of the laser induced temperature field as well as density changes due to phase transformations in the substrate are responsible for high thermal stresses, which can cause cracking and delamination, especially in the case of very hard coating materials. These stresses may be reduced by an improved process management including the integration of electro-magnetic heat sources for pre-and post-weld heating, which are able to decrease temperature gradients and cooling rates and even to suppress the undesired formation of martensite. Depending on the type of application, the stress states of single beads and surface coatings on bars and plates as well as of volume built-ups were simulated by finite element calculations, which enable an improved understanding of the physical phenomena and of the possibilities to reduce stresses by means of inductors, which are directly integrated in the cladding process. These calculations were validated by accompanying experiments, which especially deal with metallurgical phase changes, cracking, and workpiece distortion. The parameters of the inductive pre-and post-weld heating process were varied in order to reduce the input of heat into the workpiece.

Frank Brückner Dietrich Lepski Eckhard Beyer

Fraunhofer Institute for Material and Beam Technology, WinterbergstraBe 28, Dresden, 01277, Germany Fraunhofer Institute for Material and Beam Technology, WinterbergstraBe 28, Dresden, 01277, Germany

国际会议

第三届太平洋国际激光与光学应用会议(PICALO 2008)

北京

英文

88-93

2008-04-16(万方平台首次上网日期,不代表论文的发表时间)