Ti-Al基合金中的Hall-Petch关系及影响因素分析

研究了全层片状组织Ti-Al基合金的室温拉伸性能与品团尺寸的关系。Ti-Al基合金的室温拉伸屈服强度和断裂强度与晶团尺寸成Hall-Petch关系。当合金中添加替代元素Cr和Nb时，其Hall-Petch斜率不变；而添加间隙元素C和B时，其Hall-Petch斜率增加。Ti-Al基合金的室温延伸率与晶团尺寸不满足Hall-Petch关系。     

Borides at interfacial zone of IC6 TLP bonded joints

1　INTRODUCTIONTransientliquidphase (TLP)bondingtechniquehasbeensuccessfullyusedinjoiningheatresistantal loys ,likeHastelloyX ,Inconel713C ,In10 0 ,Udimet5 0 0 ,70 0 ,MarM 2 0 0 ,0 0 7,2 4 7,30 2 ,Rene′80 ,TD NiCr ,MA75 4,6 0 0 0 ,PWA14 2 2 ,CSMX 2etc ,whicharesusceptibletohotcrackingor post weldheat treatmentcrackingproblemsduringfusionweld ing[14 ] .Inaddition ,therewerereportsofjoiningNiAlandTiAlintermetallicsbyTLPbondingmethod[510 ] .Forexample ,Galehadinvestigatedthemic…     

锌铝基合金陶瓷层激光重熔区的表面温度场

使用HSC 31快速扫描红外热像仪 ,测量了含Al2 O3 表层的锌铝合金激光熔覆时的表面温度场 ,测得熔池中最高温度为 16 72℃ ,边缘温度为 6 0 0～ 70 0℃ ,冷却速率为 2× 10 3 ～ 3× 10 4 ℃ /s以及熔池形状和等温曲线。     

MIM Fe基合金的合金化强化

研究金属粉末注射成形铁基合金在强还原性氢气氛烧结条件下的合金化强化效果，结果表明，添加Ｃｕ、Ｎｉ、Ｍｏ等元素能取得显著的固溶强化效果，其中成分为Ｆｅ－２Ｎｉ－２Ｃｕ－０．４５Ｍｏ的机械性能达到σｂ＝４８３ＭＰａ，σｓ＝３４０ＭＰａ，δ＝９％和ＨＲＢ８３。     

Al2O3／TiB2／SiCW陶瓷刀具加工镍基合金时的磨损机理研究

研究了Ａｌ２Ｏ３／ＴｉＢ２／ＳｉＣＷ陶瓷刀具加工Ｉｎｃｏｎｅｌ７１８镍基合金时的切削性能和磨损机理。结果表明；在低速切削条件下，Ａｌ２Ｏ３／ＴｉＢ２／ＳｉＣＷ和硬质合金刀具的抗后刀面磨损的能力相差不大；而在高速切削条件下，前者的抗后刀面磨能力远高于后者。     

共沉淀法制备三元系铋基焦绿石型陶瓷粉体

采用改进的Mergen A．方案，用氧化锌、三氧化二铋、三氧化二锑为原料，氨水、草酸铵和碳酸铵分别为沉淀剂，盐酸为溶剂，用共沉淀法成功制备了亚微米级颗粒、高活性的铋基Bi1.5ZnSb1.5O7（BZS）焦绿石型介电陶瓷粉体。探讨了用不同的沉淀剂、在不同的烧结温度所得产物的形态。结果表明氨水做沉淀剂在570℃就可生成纯的焦绿石结构。与Mergen A方法相比成本大大降低，可以使瓷片组织的均匀性提高，电性能得到改善，电压梯度下降。     

Benchmarking Fluvial Dynamics for Process‐Based River Restoration: the Upper Rhine River (1816–2014)

Multi‐temporal analysis of river‐floodplain processes is a key tool for the identification of reference conditions or benchmarks and for the evaluation of deviations or deficits as a basis for process‐based river restoration in large modified rivers. This study developed a methodology for benchmarking fluvial processes at river segment level, focusing on those interrelations between morphodynamics (aggradation, erosion, channel shift) and vegetation succession (initial, colonization, transition) that condition habitat structure. Habitat maps of the free‐flowing Upper Rhine River downstream from Iffezheim dam (France–Germany border) were intersected with a geographic information system‐based approach. Patches showing trajectories of anthropization, changeless, progression and regression allowed for the identification of natural and human‐induced processes over almost 200 years. Before channelization, the riverine system was characterized by a shifting habitat mosaic with natural heterogeneity, high degree of surface water connectivity and equilibrium between progression and regression processes. On the other hand, the following 175 years of human interventions led to severe biogeomorphologic deficits evidenced by loss of natural processes and habitat heterogeneity, hydrological disconnection between the river and its floodplain and imbalance of progression versus regression dynamics. The main driving forces of change are found in hydromorphological impacts (channelization, regulation and hydropower plant construction). Regression processes are now almost absent and have to be the objective of process‐based river restoration measures for the studied river‐floodplain system. A sustainable view on water management and river restoration should aim at a more resilient riverine system by balancing the recovery of natural processes with societal needs. Copyright © 2016 John Wiley & Sons, Ltd.     

电冶矾土刚玉质自流浇注料的研究

以电冶矾土刚玉为骨料有利于提高浇注料的自流性能 ;六偏磷酸钠分散剂对Al2 O3泥浆流变性能有较理想的改善作用 ;电冶矾土刚玉质自流浇注料具有优良的抗渣性能 ,这主要同浇注料的显微结构和电冶矾土刚玉骨料的性能相关。     

Diffusion and sorption of benzene vapor through polybutadiene‐, polybutadiene/styrene‐, and polybutadiene/acrylonitrile‐based polyurethanes

A series of polyurethane (PU) films made from toluene diisocyanate (TDI), 1,4‐butanediol (BDO), and hydroxyl‐terminated polybutadiene (HTPB), hydroxyl terminated polybutadiene/styrene (HTBS), or hydroxyl terminated polybutadiene/acrylonitrile (HTBN) was synthesized by solution polymerization. The absorption of benzene vapor was found mainly in the soft phase. The equilibrium adsorption (M_∞) was reduced with increasing hard segment content for all the PUs. The values of M_∞ were in the sequence of HTBN‐PUs > HTBS‐PUs > HTPB‐PUs, which could be explained by the different interaction parameters between soft segments and benzene. The HTBN‐PU film showed the lowest degree of phase segregation and had more hard segments intermixed in the soft phase, restricting the movement of soft segments, and therefore resulted to non‐Fickian behavior, while the HTPB‐PU is antithetical. FTIR and atomic force microscopy were utilized to identify the hydrogen bonding behavior and morphology change of the PU films before and after the absorption of benzene vapor. The tensile strength of the HTBN‐PUs showed a greater decrease than that of HTBS‐PUs and HTPB‐PUs after absorbing benzene vapor. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2984–2991, 2004