A solidification model for prediction of castability in the precipitation-strengthened nickel-based superalloys

The Scheil equation was used to model the solidification path, microsegregation of alloying elements in the interdendritic regions, solidification temperature ranges, and to predict the formation of secondary structures and the castability behavior of as-cast superalloys. 4 experimental alloys with pre-specified γ-Ti,Nb,Al,Mo composition containing different Nb, Ti and Al contents were designed using vacuum induction melting furnace. The produced as-cast superalloys were characterized using optical and scanning electron microscopy equipped with energy dispersive X-ray spectrometer and TG–DSC analysis. The experiments showed logic conformity to the modeling results. The model and experiment confirmed the highest segregation behavior for Ti and Nb. All the experimental superalloys indicated the remarkable tendency to form secondary eutectic structures at the last stages of solidification. Superalloy with chemical composition of γ-3.5%Mo,1.8%Al,4%Ti,2.9%Nb showed the shorter solidification temperature range and the best castability.     

镍基合金中元素的ICP分析方法研究

将待测试样溶解成溶液,然后将溶液引入等离子光源使待测元素激发产生谱线,仪器根据待测元素谱线强度给出分析结果。标准规定了ICPS-1000IV型单道扫描光谱仪的分析方法。经过反复试验研究证明该方法准确度高,分析周期短。     

可编程控制在主井带式输送机上的应用

凤凰山矿主井带式输送机原采用的是传统的继电器硬布线逻辑控制方式,由于触点多、接线复杂等弱点,故障频繁,并经常出现自动停车,严重影响正常生产,该矿采用可编程控制器（ 简称ＰＬＣ） 后,解决了过去生产运输过程中的瓶颈问题,获得了很好的社会经济效益。     

Condition assessment techniques for degraded gas turbine superalloy materials

Direct and indirect methods of quantifying structural damage or residual mechanical properties have been investigated and compared for virgin Nimonic 115 and ex-service material from gas turbine blading. Whilst the indirect technique of X-ray diffraction line profile analysis exhibits a significant increase in line width with increasing creep strain, the current level of experimental scatter would need to be reduced for it to be a useful life assessment tool. The direct technique of temperature accelerated stress rupture (isostress) testing is shown to produce data which can be extrapolated to service conditions with confidence and which can be used in an assessment procedure. Stress accelerated rupture testing is demonstrated to give an unduly conservative indication of residual rupture properties at service conditions.     

酸性化学镀Ni－P合金

介绍了一种稳定性高、沉积速度较快的酸性化学镀Ｎｉ－Ｐ合金工艺．讨论了镀液组成及工艺条件对镀层沉积速度的影响，提出了化学镀Ｎｉ－Ｐ合金的最佳镀液组成和工艺条件．     

Research and development of hot-corrosion resistant superalloys

The hot-corrosion resistant superalloys have been widely applied in the gas turbines for power generation industry,the marine gas turbines in the aircraft carrier and missile destroyer as well as the aeroengines in shipboard aircraft and offshore fighter plane.Based on the ten kinds of hot-corrosion superalloys that were developed by the authors in the recent 10 years,the paper has reviewed the status and development of hot-corrosion resistant superalloys in domestic and overseas.The characteristics of chemical composition, microstructure,mechanical properties and manufacturing process are analyzed emphatically.Simultaneously the applications of hot-corrosion resistant superalloys are introduced as well.     

新型高温合金的液相连接

简要介绍了粉末冶金高温合金,定向凝固高温合金,单晶合金,镍铝系金属间化合物结构材料等新型高温合金钎焊和过渡液相扩散焊领域的发展现状,主要包括其钎料或中间层合金,连接方法及工艺和接头的高温持久性能。     

低膨胀高温合金抗氧化性能预测的研究

通过测定六种不同成分的低膨胀高温合金氧化增重曲线,提出合金元素作用系数,利用分析得到的合金元素作用系数对实验合金的氧化增重进行预测计算,其结果与实验结果吻合得很好。利用合金元素作用系数的概念和本研究所提出的方法可对低膨胀高温合金的氧化增重提供预测计算,借此可减少研究低膨胀高温合金氧化特性的试验工作量,为今后低膨胀高温合金的发展打下了基础。     

The alloying mechanisms of Re, Ru in the quaternary Ni-based superalloys interface: A first principles calculation

The site preference of Re, Ru on the γ/γ^′ interface and their influence on the partitioning behaviors of W, Mo in the γ and γ^′ phase have been investigated by DMol3 calculation. The transfer energy results show that both Re and Ru exhibit a weak Ni site preference. When Re substitutes Ni on the γ/γ^′ interface, it is found a reverse partitioning behavior of W, while the partitioning behavior of Mo was not affected. In contrast, Ru’s substitution for Ni on the interface does not affect the partitioning behaviors of W, Mo, which is in agreement with experimental results. In addition, the different interface strengthening mechanisms for Re and Ru are investigated by the electronic structure analysis of the Mulliken population, the impurity-induced charge redistribution and the partial density of states. Results show that the alloying strengthening effect of Re is mainly due to the direct bonding of Re and the host atoms. Whereas, the addition of Ru is effective for improving the phase stability of Ni-based superalloys.     

镍基单晶高温合金凝固组织特征的研究进展

镍基单晶高温合金的凝固组织对其最终的高温力学性能有着重要的影响,由于制造工艺条件限制,单晶高温合金的制备和加工中总会出现杂晶,保持单晶结构的完整性对提高单晶合金的冶金质量和降低维护成本具有重要意义.综述了镍基单晶高温合金在铸造、焊接、表面熔凝工艺条件下的凝固组织特征的研究现状,分析了工艺条件、工艺参数等对凝固组织和性能的影响,并展望了杂晶缺陷的控制、实现单晶叶片连接区的单晶化.