Product Code: ICAL05_610

Laser Deposition of Refractory Mo-Ni Alloy
Authors:
Minlin Zhong, Tsinghua University; Beijing China
Ting Huang, Tsinghua University; Beijing China
Wenjin Liu, Tsinghua University; Beijing China
Presented at ICALEO 2005

Laser direct deposition is good at manufacturing specific metallic components like refractory metal component with complicated geometry, which is very difficult or impossible by conventional method.
The paper presents research on producing high melting point Molybdenum alloy component by laser deposition. The temperature in a laser deposition melt pool is usually less than the melting point of Mo, so the fed Mo powder will not melt but dissolve into the melt pool. It is important to understand the dissolution behavior and optimized conditions before a good deposition results are possible. The melting and dissolution characteristics of M-Ni alloy in the melt pool, the multipass deposition capability, the parameter optimization, the microstructure features on laser deposition of Mo alloy were investigated. Mo21Ni79 alloy shows a good forming capability for deposition. With optimized parameters (laser power of 1800W, beam diameter of 3 mm , scanning speed of 3 m/ min and powder feed rate of 4 g/min, a square shaped sample with length of 30 mm , width of 30mm, height of 6 mm was deposited. No cracks and porosities occurred on the surface. SEM analysis indicates some Mo particles are not melted during the laser processing. Cracks can be observed in multi-layer deposition. X-rays diffraction result indicates that the main phase of the deposited sample is Mo6Ni6C1.06. The results proved that laser direct deposition could be used to manufacture refractory metal components.