Karahasan Betul, Dogan Derya Ozdemir, Babacan Nazim
Int J Prosthodont. 2025 Jul 21;0(0):1-19. doi: 10.11607/ijp.9332.
The purpose of this in vitro study was to evaluate the effects of laser power on the relative density, surface roughness, and metal-ceramic bond strength of Co-Cr alloys produced by selective laser melting (SLM), following a single laser track analysis to determine suitable processing parameter window.
Single track laser melting was performed at various laser powers and scanning speeds using SLM. Subsequently, three different laser powers (240 W, 300 W, 360 W) were used to produce 12×12×10 mm cube specimens and 25×3×0.5 mm metal strips. The density of the cube specimens (n=5) was determined using the Archimedes method. Microstructural investigations were conducted after metallographic preparation using scanning electron microscope (SEM). Surface roughness of the sandblasted metal strip specimens (n=9) was measured. Ceramic was applied to metal specimens (n=10) in each group, and the strength of the metal-ceramic bond was evaluated through a three-point bend test.
SEM analysis showed improved laser track clarity, thickness, and continuity with increasing laser power from 240 W to 360 W. Relative density exceeded 99% for all specimens, with no significant group differences (P=.90). Higher laser power caused keyhole formation and increased surface roughness, peaking at 11.89 ± 3.86 Sa for the P360 group (P<0.01). Specimens produced with the highest laser power demonstrated stronger and more consistent metal-ceramic bond strengths, with significant differences observed between the highest (360 W) and the lowest (240 W) power group (P<.05).
While increased laser power enhanced surface roughness and strength of the metal-ceramic bond, it did not lead to substantial changes in the relative density of the specimens.
本体外研究的目的是评估激光功率对选择性激光熔化（SLM）制备的钴铬合金的相对密度、表面粗糙度和金属陶瓷结合强度的影响，通过单激光轨迹分析来确定合适的加工参数窗口。
使用SLM在不同激光功率和扫描速度下进行单轨迹激光熔化。随后，使用三种不同的激光功率（240W、300W、360W）制备12×12×10mm的立方体试样和25×3×0.5mm的金属条。使用阿基米德法测定立方体试样（n = 5）的密度。金相制备后，使用扫描电子显微镜（SEM）进行微观结构研究。测量喷砂处理的金属条试样（n = 9）的表面粗糙度。在每组的金属试样（n = 10）上施加陶瓷，并通过三点弯曲试验评估金属陶瓷结合的强度。
SEM分析表明，随着激光功率从240W增加到360W，激光轨迹的清晰度、厚度和连续性得到改善。所有试样的相对密度均超过99%，组间无显著差异（P = 0.90）。较高的激光功率导致匙孔形成并增加表面粗糙度，P360组的表面粗糙度峰值为11.89±3.86 Sa（P < 0.01）。使用最高激光功率制备的试样表现出更强且更一致的金属陶瓷结合强度，最高（360W）和最低（240W）功率组之间存在显著差异（P < 0.05）。
虽然激光功率增加会提高金属陶瓷结合的表面粗糙度和强度，但不会导致试样相对密度的显著变化。
