Fatigue strength of Co-Cr-Mo alloy clasps prepared by selective laser melting
Fatigue strength of Co-Cr-Mo alloy clasps prepared by selective laser melting
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DOI：
10.1016/j.jmbbm.2016.02.032
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发表时间：
2016-06-01
影响因子：
3.9
通讯作者：
Wakabayashi, Noriyuki
中科院分区：
文献类型：
--
作者：
Kajima, Yuka;Takaichi, Atsushi;Wakabayashi, Noriyuki
研究选择性激光熔化法制备可摘局部义齿Co-Cr-Mo卡环的疲劳强度。拉伸试验用的Co-Cr-Mo合金试样（哑铃试样）和疲劳试验用的疲劳试样（卡扣试样）采用SLM法制备，试样与建筑物的纵向夹角分别为0°（TLO、FLO）、45°（TL45、FL45）和90°（TL90、FL90）。卡扣试件进行0.25 mm和0.50 mm的10(6)次循环变形。SLM试样在拉伸试验中没有表现出明显的力学各向异性，在所有条件下均表现出明显高于铸态试样的屈服强度和极限抗拉强度。相反，发现了与构建方向相关的高度各向异性疲劳性能。对于0.50 mm挠度下的试样，FL90的疲劳寿命（205,418次）明显长于铸造试样（112,770次）。相比之下，FLO（28,484次）和FL45（43,465次）的疲劳寿命明显较短。FLO和FL45的表面粗糙度显著高于铸态，而FL90与铸态的表面粗糙度差异不显著。电子背散射衍射（EBSD）分析表明，FLO晶粒沿法向向断口方向优先接近γ相< 001 >取向。FL45和FL90晶粒的择优取向不明显。因此，疲劳强度可能受到许多因素的影响，包括表面粗糙度和晶体取向。只要采用合适的构建方向，SLM工艺是制备坚韧的可移动局部义齿框架的有希望的候选工艺。(C) 2016 Elsevier Ltd.版权所有。
We aimed to investigate the fatigue strength of Co-Cr-Mo clasps for removable partial dentures prepared by selective laser melting (SLM). The Co-Cr-Mo alloy specimens for tensile tests (dumbbell specimens) and fatigue tests (clasp specimens) were prepared by SLM with varying angles between the building and longitudinal directions (i.e., 0 degrees (TLO, FLO), 45 degrees (TL45, FL45), and 90 degrees (TL90, FL90)). The clasp specimens were subjected to cyclic deformations of 0.25 mm and 0.50 mm for 10(6) cycles. The SLM specimens showed no obvious mechanical anisotropy in tensile tests and exhibited significantly higher yield strength and ultimate tensile strength than the cast specimens under all conditions. In contrast, a high degree of anisotropy in fatigue performance associated with the build orientation was found. For specimens under the 0.50 mm deflection, FL90 exhibited significantly longer fatigue life (205,418 cycles) than the cast specimens (112,770 cycles). In contrast, the fatigue lives of FLO (28,484 cycles) and FL45 (43,465 cycles) were significantly shorter. The surface roughnesses of FLO and FL45 were considerably higher than those of the cast specimens, whereas there were no significant differences between FL90 and the cast specimens. Electron backscatter diffraction (EBSD) analysis indicated the grains of FLO showed preferential close to < 001 > orientation of the gamma phase along the normal direction to the fracture surface. In contrast, the FL45 and FL90 grains showed no significant preferential orientation. Fatigue strength may therefore be affected by a number of factors, including surface roughness and crystal orientation. The SLM process is a promising candidate for preparing tough removable partial denture frameworks, as long as the appropriate build direction is adopted. (C) 2016 Elsevier Ltd. All rights reserved.