Co对CuNiSi合金应力松弛行为的影响

发布时间：2018-10-04 22:57

【摘要】：采用悬臂梁弯曲应力松弛测试方法对CuNiSiCo合金的应力松弛性能进行了测试,利用TEM探究Co对CuNiSi合金应力松弛组织的影响,并建立了应力松弛模型。结果表明,应力松弛过程可动位错密度是降低的经验公式σ*=[K′ln(t+a0)+C]-n的模拟结果,与实验结果基本相符;合金松弛分为2个阶段,第一阶段应力松弛速率较大,由于在应力松弛的初期阶段,可动位错数量很多,位错移动的阻力比较小,位错移动的驱动力比较大;第二阶段,应力松弛速率较小,处于缓慢松弛阶段,这一阶段位错与杂质原子以及位错与第二相粒子发生交互作用,使位错增殖;Co在Cu中的固溶度较小且易于与空位结合,从而抑制了调幅分解形成所需的空位移动,致使含Co元素的CuNi-Co-Si铜合金空位大量减少,抑制了可动位错的滑移;另一方面,促进了基体中析出相的析出,析出相弥散均匀地分布在合金基体中,在发生应力松弛过程中,移动的可动位错在遇到弥散分布的第二相之后,会被第二相所钉扎,故Co替代部分Ni形成的CuNiSiCo合金的应力松弛性能要优于CuNiSi合金。
[Abstract]:The stress relaxation properties of CuNiSiCo alloy were tested by means of cantilever beam bending stress relaxation test. The effect of Co on stress relaxation structure of CuNiSi alloy was investigated by TEM, and a stress relaxation model was established. The results show that the movable dislocation density of the stress relaxation process is the simulated result of the reduced empirical formula 蟽 n = [K'ln (t a 0 C] -n, which is in good agreement with the experimental results, and the alloy relaxation is divided into two stages, and the stress relaxation rate of the first stage is larger. In the early stage of stress relaxation, the number of movable dislocations is large, the resistance of dislocation movement is relatively small, the driving force of dislocation movement is relatively large, and in the second stage, the stress relaxation rate is relatively small and is in the slow relaxation stage. In this stage, the dislocation interacts with the impurity atom and the dislocation with the second phase particle, which makes the dislocation proliferate Co in Cu less solid solution and easy to bind to the vacancy, thus inhibiting the vacancy movement needed for the amplitude modulation decomposition. As a result, the vacancy of CuNi-Co-Si copper alloy containing Co element is greatly reduced, and the slippage of movable dislocation is restrained. On the other hand, it promotes the precipitation of precipitated phase in matrix, and the precipitated phase distributes uniformly in the alloy matrix, and during the process of stress relaxation, The movable dislocation is pinned by the second phase when it encounters the second phase of dispersion distribution, so the stress relaxation property of the CuNiSiCo alloy formed by Co replacing part of Ni is better than that of CuNiSi alloy.
【作者单位】：江西理工大学工程研究院;江西理工大学材料科学与工程学院;
【基金】：国家“863”项目资助(2006AA03Z522) 江西省教育厅项目(GJJ14447)
【分类号】：TG146.11

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