Effects of loading rates, notch root radius and specimen thickness on fracture toughness in bulk metallic glasses
Effects of loading rates, notch root radius and specimen thickness on fracture toughness in bulk metallic glasses
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DOI：
10.1016/j.jallcom.2006.08.328
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发表时间：
2007-05
影响因子：
6.2
通讯作者：
K. Fujita;A. Okamoto;N. Nishiyama;Y. Yokoyama;H. Kimura;A. Inoue
中科院分区：
文献类型：
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作者：
K. Fujita;A. Okamoto;N. Nishiyama;Y. Yokoyama;H. Kimura;A. Inoue
通过断裂韧性（KQ）测试研究了加载速率（K stec）、缺口根部半径（R）和试样厚度（B）对Zr基大块非晶合金（BGA）KQ值的影响。Zr 50 Cu 40 Ni 10at.%的BMG的平面应变断裂韧性KIC在满足ASTM E399的条件下，通过电弧倾斜铸造法制备的SiO2显示出53 MPam 1/2的大值。当K stecof约为0.1MPam1/2s−1时，有情况下KQ表现出超过100 MPam 1/2。当R <30μm时，KQ随R的增大而增大，当R> 90μm时，KQ大于120 MPam 1/2。当B从2.3 mm减小到0.12 mm时，KQ略有下降。在这些情况下，估计的平面应力塑性区的大小与试样表面上的疲劳裂纹尖端或缺口根部附近的剪切带的长度吻合得很好。
The fracture toughness (KQ) tests were carried out in order to study the effect of loading rate (K˙), notch root radius (R) and specimen thickness (B) on the KQin Zr-based bulk glassy alloys (BGAs). The plane strain fracture toughness KICof the BMG of Zr50Cu40Ni10at.% prepared by an arc tilt casting method showed a large value of 53MPam1/2under the conditions satisfying ASTM E399. With K˙ of about 0.1MPam1/2s−1, there were cases that the KQexhibited more than 100MPam1/2. The KQincreased with increasing R even for smaller R of 30μm, and KQexhibited more than 120MPam1/2with R of more than 90μm. KQdecreases a little with decreasing the B from 2.3 to 0.12mm was shown. In these cases, the estimated plane stress plastic zone sizes agreed well with the length of shear bands near the fatigue crack tips or notch roots on specimen surfaces.