Effects of Process Parameters on the Structure and Hardness of Components in Laser Direct Metal Forming

Abstract

As a typical additive manufacturing (AM) technology, Laser Metal Direct Forming(LMDF) integrates the characteristics of laser cladding technology and rapid prototyping technology. Because LMDF process has important application value in the field of rapid mould manufacturing and additive remanufacturing process, the effects of main technological parameters (laser power, powder feeding rate and scanning speed) on the microstructure and hardness in the process of forming were studied. To verify this influence rule, the experimental study on LDMF with different process parameter combinations were carried out with 45 steel as matrix and iron-based alloy powder as cladding material. Experimental results was consistent with the theoretical analysis results. In a word, experiments show that LMDF process can obtain uniform and compact metal cladding layer. The forming process parameters and their reasonable matching are closely related to the structure and performance of components. With the increase of laser power, the grain size of metallographic structure increases and the hardness decreases. To a certain extent, properly increasing the scanning speed and powder feeding rate can refine the grain size of metallographic structure, which increased the hardness of the component and enhancing its surface wear resistance.