Origin of the Significant Impact of Ta on the Creep Resistance of FeCrNi Alloys
D. Magne, X. Sauvage, M. Couvrat
发表信息：
148th Annual Meeting & Exhibition of The Minerals, Metals & Materials Society, TMS (The Minerals, Metals & Materials Society), Mar 2019, San Antonio, United States. pp.1057-1066
Heat resistant FeCrNi alloys are widely used in the petrochemical industry because they exhibit a unique combination of creep and oxidation resistance at temperatures exceeding 900$^\circ$C. Their creep properties are often optimized by micro-additions of carbide forming elements. In the present work, the influence of Ta micro-additions has been experimentally investigated both on as-cast and aged microstructures to understand the origin of the significant impact of this element on the creep resistance. Calculations with thermocal software were also carried out to support experimental data. It is shown that a small addition of Ta is beneficial as it increases the volume fraction of stable MC carbides. We demonstrate also that additions of Ta may have a dramatic effect on the thermal stability of microstructures. This is attributed to a smaller equilibrium volume fraction of M23C6 and more pronounced heterogeneous precipitation at MC/matrix interfaces. The influence on the creep properties in then discussed.
Creep Behavior of High-Entropy Alloys: A Critical Review
University of California（加州大学）；University of Bayreuth（拜罗伊特大学）；Karlsruhe Institute of Technology (KIT)（卡尔斯鲁厄理工学院）；University of Tennessee, Knoxville（田纳西大学诺克斯维尔分校）；Ruhr University Bochum（波鸿鲁尔大学）
Insights into hydrogen-induced vacancy stability and creep in chemically complex alloys
Ames National Laboratory, US Department of Energy, Iowa State University（艾姆斯国家实验室，美国能源部，爱荷华州立大学）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；Department of Materials Science & Engineering, Iowa State University（爱荷华州立大学材料科学与工程系）
Evolution of interfacial dislocation network during low-stress high temperature creep of particle strengthened alloy system using discrete dislocation dynamics simulations
High-Ti induced planar-fault transformation toward superlattice extrinsic stacking faults and microtwins in crept CoNi-based superalloys
Helmholtz-Zentrum Hereon（赫尔姆霍茨-海雷恩中心）；Tsinghua University（清华大学）；University of Stuttgart（斯图加特大学）；University of Twente（特文特大学）；Southeast University（东南大学）；Central South university（中南大学）
Spark Plasma Sintering for high-speed diffusion welding of the ultrafine grained near-a Ti-5Al-2V alloy with high strength and corrosion resistance for nuclear engineering
Vacancy formation energies and migration barriers in multi-principal element alloys
多主元素合金（MPEAs）由于其结构稳定性和抗辐射损伤能力的提高，作为结构和面向等离子体的材料继续受到关注。尽管机械行为对辐照和点缺陷形成的敏感性，但对基于耐火材料的MPEAs中空位稳定性和扩散的理解很少关注。利用密度泛函理论研究了体心立方（Mo 0.95 W 0.05）0.85 Ta 0.10（TiZr）0.05中空位的稳定性和扩散势垒.在这个MPEA中的结果显示出强烈的环境依赖性，源自与相邻原子之间的电荷转移相关的局部晶格畸变，该电荷转移随不同的化学环境而变化。我们发现晶格畸变程度和迁移势垒之间的相关性：（Ti，Zr）具有较小的畸变具有较低的势垒，而（Mo，W）具有较大的畸变具有较高的势垒，这取决于局部环境。在辐照下，我们的研究结果表明，（Ti，Zr）是显着更容易扩散比（Mo，W），而Ta显示中间效果。因此，由空位扩散引起的材料退化可以通过调整合金元素的组成来控制，以提高在极端操作温度和苛刻条件下的蠕变强度。
Effect of ageing on the properties of the W-containing IRIS-TiAl alloy
研究了800 ℃时效对IRIS合金（Ti $_{49.9}$ Al $_{48}$ W $_2$ B $_{0.1}$）性能的影响。放电等离子烧结（SPS）致密化后的合金初始组织主要由片层团组成，片层团周围包裹着$γ$晶粒。通过力学性能试验，测定了时效处理后合金强度和抗蠕变性能的变化。显微结构的变化进行了研究，通过扫描和透射电子显微镜和X射线衍射。主要的组织演变包括片层区域的收缩和$β_0$相的析出，这伴随着钨的适度偏析和$α_2$片层宽度的减小。然而，这些演变是相对有限的，显微组织的稳定性被发现主要是由于钨的低扩散率。相反，在室温和高温下，测量这种时效处理对机械性能的适度影响。这样的实验结果解释和讨论的微观结构的演变和变形机制，在不同的温度下激活各种solicitations。
