23 research outputs found
Comparison of Sublimation 3D Scanning Sprays in Terms of Their Effect on the Resulting 3D Scan, Thickness, and Sublimation Time
This study compared eight sublimation scanning sprays in terms of their effect on 3D scanning results, coating thickness, and sublimation time. The work used an automated spraying system to ensure the same deposition conditions for all tested materials. All experiments were performed under the same environmental conditions to exclude the influence of the ambient environment on the coatings. All tested scanning sprays created coatings with thicknesses in the order of tens of micrometers that were detectable by the 3D scanner Atos III Triple Scan. The coatings must be applied carefully when accurate measurements are required. All used materials enabled the capture of the highly reflective surface of the Si-wafer. However, the differences between some sprays were significant. Sublimation time measurements showed that all coatings disappeared from the Si-wafer surface completely. Nevertheless, all coatings left visible traces on the mirror-like surface. They were easily wiped off with a cloth
Selective Laser Melting Strategy for Fabrication of Thin Struts Usable in Lattice Structures
This paper deals with the selective laser melting (SLM) processing strategy for strut-lattice structure production which uses only contour lines and allows the porosity and roughness level to be managed based on ombination of the input and linear energy parameters
Effect of Process Parameters and High-Temperature Preheating on Residual Stress and Relative Density of Ti6Al4V Processed by Selective Laser Melting
The aim of this study is to observe the effect of process parameters on residual stresses
and relative density of Ti6Al4V samples produced by Selective Laser Melting. The investigated
parameters were hatch laser power, hatch laser velocity, border laser velocity, high-temperature
preheating and time delay. Residual stresses were evaluated by the bridge curvature method and
relative density by the optical method. The effect of the observed process parameters was estimated
by the design of experiment and surface response methods. It was found that for an effective
residual stress reduction, the high preheating temperature was the most significant parameter. High
preheating temperature also increased the relative density but caused changes in the chemical
composition of Ti6Al4V unmelted powder. Chemical analysis proved that after one build job with
high preheating temperature, oxygen and hydrogen content exceeded the ASTM B348 limits for
Grade 5 titanium