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Fatigue Crack Propagation in Composite Resins

复合树脂中的疲劳裂纹扩展

基本信息

批准号：
04454469
负责人：
TSUCHITANI Yasuhiko
金额：
$ 4.48万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04454469/
关键词：
Composite resin Fatigue crack Fracture mechanics 疲労強度破壊靭性

项目摘要

1.The Paris law (da/dN=C(DELTA K)^m) could be applied to the fatigue crack growth rate of the materials used in this study. Constant m was in the range of 24.3-32.2 for composite resins and 19.7-21.0 for unfilled resins. The DELTA K_<th> was in the range of 0.43-0.82 MPa・m^<1/2> for composite resins and 0.20-0.21MPa・m^<1/2> for unfilled resins. Constant m of dental composites was extremely higher than that of metal(m=2-7), but did not differ very much from each other. The fatigue crack growth rate of dental composites depended on DELTA K_<th> rather than constant m. 2.Microstructural examination of fatigue fracture surfaces by SEM indicated that the fatigue crack of dental composites propagated along the interface between inorganic filler and matrix, and that some organic fillers were penetrated with fatigue cracks.3.Fatigue crack growth rate was more sensitive to degradation of composites by aging in water than transverse strength.4.The fatigue resistance of composites measured as DELTA K_<th> decreased by aging in water. SEM observation showed that fatigue crack propagated in both matrix and filler-matrix interface after aging in water for three months.These results indicated that that crack deflection and crack bridging by inorganic filler increased the fatigue resistance of composites, and that decrease of fatigue resistance by aging in water was caused by the degradation of resin matrix. From the present study, it was shown that the fatigue crack propagation test was an effective method to investigate toughening and degradation of dental composites.

1.巴黎定律（da/dN=C（DELTA K）^m）可应用于本研究中所用材料的疲劳裂纹扩展速率。复合树脂的常数m为24.3-32.2，未填充树脂的常数m为19.7-21.0。复合树脂的Δ K_（<th>max）在0.43-0.82 MPa·m^<1/2>之间，未填充树脂的Δ K_（max）在0.20- 0.21 MPa·m^<1/2>之间。牙科复合材料的常数m远高于金属（m=2-7），但彼此差异不大。牙科复合材料的疲劳裂纹扩展速率与Δ K有关，<th>而与常数m无关。2.疲劳断口的扫描电镜观察表明，复合材料的疲劳裂纹沿着无机填料与基体的界面扩展，部分有机填料与疲劳裂纹一起穿透; 3.复合材料的疲劳裂纹扩展速率对水中老化的敏感性大于横向强度; 4.复合材料的疲劳抗力<th>随水中老化的进行而降低。SEM观察表明，复合材料在水中老化3个月后，疲劳裂纹在基体和填料-基体界面扩展，表明无机填料的裂纹偏转和裂纹桥接提高了复合材料的疲劳抗力，而水中老化导致复合材料疲劳抗力下降的原因是树脂基体的降解。疲劳裂纹扩展试验是研究牙科复合材料增韧和降解的有效方法。