Abstract
Purpose - This paper explores selective laser melting of yttria stabilized zirconia ceramic by a 1µm wavelength fiber laser, and investigates the influence of different laser powers and different scanning velocities on the microstructure, the relative density, the deformation of ceramic sample, the micro-hardness, and it analyses the crystal structure transformation during the fabrication. Design/methodology/approach - During the fabrication, the 5mm×5mm×5mm YSZ ceramic samples are fabricated by RP machine MCP realizer SLM 250, density and microscopic photographs shows the ceramic melting situation. The density of cubic sample with different laser power and different scanning velocities is measured by Archimedes method, The microstructure of samples and powder is observed by SEM. The micro-hardness is measured by the Vickers microhardness equipment, and the crystal structure transition is research by XRD.Findings - It’s possible to melt YSZ powder completely with near IR fiber laser, and the relative density of 5mm×5mm×5mm cubic sample is 88%, the micro-hardness could reach 1209±262HV500. And the influence of laser power on the volume deformation is more sensitive than the scanning speed at the same energy density. The small pores and the obvious orderly cracks can be observed in the cross section of sample, the uneven distribution of laser energy input is the main reason of the formation of orderly cracks. The transformation from monoclinic and cubic crystal to tetragonal crystal occurred during the melting process. Heat treatment (1400?-30min) cannot significantly improve the density of the sample, but it can restore the color of ceramic.Research limitations/implications - Particularly serious due to the deformation of the ceramic material, so we can not prepare a large ceramic samples and measure its macroscopic mechanical properties.Originality/value - This paper manufactures YSZ ceramic sample by sls technology with a 1µm wavelength fiber laser, and preliminary studies the microscopic structure, distribution of laser parameters and crystal transformation.
Purpose - This paper explores selective laser melting of yttria stabilized zirconia ceramic by a 1µm wavelength fiber laser, and investigates the influence of different laser powers and different scanning velocities on the microstructure, the relative density, the deformation of ceramic sample, the micro-hardness, and it analyses the crystal structure transformation during the fabrication. Design/methodology/approach - During the fabrication, the 5mm×5mm×5mm YSZ ceramic samples are fabricated by RP machine MCP realizer SLM 250, density and microscopic photographs shows the ceramic melting situation. The density of cubic sample with different laser power and different scanning velocities is measured by Archimedes method, The microstructure of samples and powder is observed by SEM. The micro-hardness is measured by the Vickers microhardness equipment, and the crystal structure transition is research by XRD.Findings - It’s possible to melt YSZ powder completely with near IR fiber laser, and the relative density of 5mm×5mm×5mm cubic sample is 88%, the micro-hardness could reach 1209±262HV500. And the influence of laser power on the volume deformation is more sensitive than the scanning speed at the same energy density. The small pores and the obvious orderly cracks can be observed in the cross section of sample, the uneven distribution of laser energy input is the main reason of the formation of orderly cracks. The transformation from monoclinic and cubic crystal to tetragonal crystal occurred during the melting process. Heat treatment (1400?-30min) cannot significantly improve the density of the sample, but it can restore the color of ceramic.Research limitations/implications - Particularly serious due to the deformation of the ceramic material, so we can not prepare a large ceramic samples and measure its macroscopic mechanical properties.Originality/value - This paper manufactures YSZ ceramic sample by sls technology with a 1µm wavelength fiber laser, and preliminary studies the microscopic structure, distribution of laser parameters and crystal transformation.
