Experiments On Laser Engineered Net Shaping Of ZrO₂Matrix Composite Ceramic With Alumina

Laser Engineered Net Shaping (LENS) is an advanced manufacturing technology, which can automatically fabricate complex-shaped parts directly from CAD files without using any modules or tools by the utilization of laser cladding technique with automatic powder feeding. Ceramic parts having many good performances of high melting point、high hardness、 high temperature thermostability、 corrosion resistance、 wear resistance and chemical stability, are widely used in many significant fields, such as mechanical, electronic, oil, aerospace and biomedical engineering. Especially in extreme environment of High temperature corrosion, insulation and high wear in national defense、 high-tech fields. Ceramic parts using LENS can be rapidly net shaping manufactured without binding element. Not only production cycle is further reduced, but also the density of ceramic is increased, reduced cracks caused by the subsequent processing. In this paper, the study of ceramic LENS processes will be carry on using ZrO2and Al2O3powder, with analysis of interaction between laser and powder, and problems of crack and pore. The microstructure、element distribution and phase transformation will be tested by the means of optical microscope、 electron microprobe and XRD. The research contents are as follows:(1) The single element experiment of LENS using ZrO2powder will be conducted. The effects of main parameters such as laser power, scanning velocity, powder feeding rate on the shape of cladding layers’cross-sections will be discussed.(2) The basic research of ceramic thin-wall formed by LENS will be carried on using ZrO2and Al2O3powder. The research of ceramic quality will be conducted from two aspects of Al2O3amount and process parameters. Al2O3amount will be added0、13wt.%、30wt.%、45wt.%. The rules and effect of process parameters on crack and porosity in ceramic thin-wall will be analyzed.(3) The microstructures of ceramic coating and thin-wall will be analyzed through Optical Microscope, SEM and electron probe, particularly in bond of ceramic and substrate, ceramic grain and grain boundary. The change and cause of ceramic grain with Al2O3amount will be studied.In this paper, rapid manufacture of ceramic thin-wall part has been achieved using LENS without binding element and sintering. This greatly reduces the product manufacturing cycle. The effect of Al2O3amount and process parameters on ceramic quality such as surface, crack, porosity, has researched. And this will has a guiding significance for rapid manufacture of ceramic part using LENS.