The effect of strain rate and temperature on the tensile properties of NiAl
The effect of strain rate and temperature on the tensile properties of NiAl
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DOI：
10.1557/jmr.1992.0605
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发表时间：
1992-03
影响因子：
2.7
通讯作者：
R. Noebe;C. L. Cullers;R. Bowman
中科院分区：
文献类型：
--
作者：
R. Noebe;C. L. Cullers;R. Bowman
在300 ~ 900 K温度范围内，以1.4 × 10^-4 ~ 1.4 × 10^-1 × s^-1的应变速率对铸造和挤压的二元NiAl合金进行拉伸试验。的脆韧性转变温度（BDTT）是依赖于应变速率，与应变速率的三个数量级的增加，导致约200 K的转变温度增加。无论应变速率如何，在刚好高于BDTT的温度下，断裂强度显著增加，并且断裂形态从主要沿晶变为主要穿晶。还确定了负责NiAl中脆韧性转变的机制具有约118 kJ/mol的表观活化能。这些结果支持的论点，即在NiAl的脆韧性转变的机制是与热激活变形过程的开始。这一过程可能是由短路扩散控制的位错攀移过程。
Tensile testing of cast and extruded binary NiAl was performed from 300 to 900 K at strain rates of 1.4 × 10^−4 to 1.4 × 10^−1 × s^−1. The brittle-to-ductile transition temperature (BDTT) was dependent on strain rate, with a three order of magnitude increase in strain rate resulting in approximately a 200 K increase in transition temperature. Regardless of strain rate, at temperatures just above the BDTT the fracture strength increased significantly and the fracture morphology changed from mostly intergranular to predominantly transgranular. It was also determined that the mechanism responsible for the brittle-to-ductile transition in NiAl had an apparent activation energy of approximately 118 kJ/mol. These results support the argument that the mechanism for the brittle-to-ductile transition in NiAl is associated with the onset of a thermally activated deformation process. This process is probably dislocation climb controlled by short circuit diffusion.