Hardness, chemical and microstructural studies for laser-fabricated metal parts of graded materials

摘要

Laser deposition of metal layers has been recognized in recent years as a one-step process to fabricate metal parts instead of the two-step process of producing a mold and then using the mold to cast a metal part. The authors have employed this one-step technique to create graded materials by varying the part's composition from 100 % stainless steel to a 100 % nickel-based superalloy. Mechanical properties of these graded materials are measured and the effects of slow solidification rates are investigated. A multimode CO_2 laser is operated at 270 W to produce wall-like structures of graded materials. The CO_2 laser beam is focused to a spot size of 600μm using a 127 mm focal length lens.