Quantitative correlation between fracture toughness K1C and the short-term strength σb, σ0·2 of tungsten
Quantitative correlation between fracture toughness K1C and the short-term strength σb, σ0·2 of tungsten
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DOI：
10.1007/bf00805552
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发表时间：
1983-11
期刊：
影响因子：
--
通讯作者：
A. Babak
中科院分区：
文献类型：
--
作者：
A. Babak
商业纯钨，特别是粉末冶金法生产的V-MP合金，目前被广泛用作现代技术部件的结构材料。这种材料的一个显著特征是它在晶界处含有裂纹状缺陷[i]。在通过高温铸造[i]制造钨的过程中，材料中可能会出现缺陷，或者缺陷集中在材料中的杂质周围[2]。一些工作是基于在热机械作用过程中由于内应力在晶界处发生微裂纹的可能性[3-5]。参考文献[6]的数据表明，V-MP合金在中高温下的裂纹发展主要沿沿着晶界发生。所研究的合金的一个特性是其高温脆化倾向，导致晶界结合的弱化[3，7]。现代技术中的部件在非常复杂的温度-力效应条件下工作。因此，在钨件的使用过程中，外部应力场中出现有利于缺陷发展的条件。构件的使用性能取决于其对裂纹发展的抵抗力，即断裂韧性。换句话说，考虑到钨在热机械作用过程中的结构变化及其损伤特征，可以认为钨的强度最终取决于其断裂韧性。在这种情况下，表征断裂韧性的参数和表征材料短期强度的参数之间应该存在定量关系。
Commercially pure tungsten, particularly alloy V-MP produced by a powder metallurgical method, is currently widely used as a structural material for components of moden technology. A distinguishing feature of this material is that it contains cracklike defects at grain boundaries [i]. Defects can occur in the material during fabrication of tungsten by high-temperature casting [i], or are concentrated around impurities in the material [2]. Some works are based on the possibility of microcrack occurrence at grain boundaries due to internal stresses ocurring during thermomechanical action [3-5]. The data of reference [6] indicate that crack development in a V-MP alloy at intermediate and high temperatures occurs predominantly along grain boundaries. A characteristic of the alloy under study is its tendency for hightemperature embrittlement, leading to a weakening of grain-boundary bonding [3, 7].Components in modern technology operate under conditions of verycomplex temperature--force effects. Consequently, during use of tungsten pieces, conditions occur favorable for the development of defects in an external stress field. The serviceability of a piece is determined by its resistance to the development of cracks, ie, to its fracture toughness. In other words, considering the structural changes in tungsten during thermomechanical action and the character of its damage, it can be supposed that the strength of tungsten is ultimately determined by its fracture toughness. In this case, there should be a quantitative relationship between the parameters characterizing the fracture toughness and those characterizing the short-term strength of the material.