WC—20（Fe／Co／Ni）硬质合金断裂韧性的一种测定方法和断裂模式研究

用电火花加工的单边缺口试样，外推得到ＷＣ－２０（Ｆｅ／Ｃｏ／Ｎｉ）硬质合金的平面应变断裂韧性ＫＩＣ，发现表观裂纹扩展能量释放率ＣＱ（ρ）与试样缺口根部曲率半径ρ呈线性关系，即ＧＱ（ρ）＝ＧＩＣ＋Ａρ。在扫描电镜下观察断口形貌，认为有４种断裂模式：粘结相撕裂、ＷＣ晶闰解理断裂、ＷＣ－ＷＣ晶界开裂和ＷＣ－粘结相边界开裂，讨论了各种断裂模式的断裂过程。     

粘结剂成分对WC—20（Fe／Co／Ni）硬质合金力学性能和显微组织的影响

用常规的粉末冶金工艺试制了四种成分的ＷＣ－２０（Ｆｅ／Ｃｏ／Ｎｉ）合金，优选粘结剂的成分及总碳量可使其力学性能最佳。着重研究了ＷＣ－２０（Ｆｅ／Ｃｏ／Ｎｉ）合金的力学性能和显微组织，发现粘结相为孪晶马氏体和奥氏体时，其主要力学性有不低于ＷＣ－２Ｃｏ，而粘结相全部为板条马氏体时，其主要力学性能低于ＷＣ－２Ｃｏ。     

粘结剂成分对WC－20（Fe／Co／Ni）硬质合金力学性能和显微组织的影响

用常规的粉末冶金工艺试制了四种成分的ＷＣ－２０（Ｆｅ／Ｃｏ／Ｎｉ）合金，优选粘结剂的成分及总碳量可使其力学性能最佳。着重研究了ＷＣ－２０（Ｆｅ／Ｃｏ／Ｎｉ）合金的力学性能和显微组织，发现：粘结相为李晶马氏体和奥氏体时，其主要力学性能不低于ＷＣ－２Ｃｏ；而粘结相全部为板条马氏体时，其主要力学性能低于ＷＣ－２Ｃｏ     

少量A1对WC－13％Fe／Co／Ni硬质合金性能和组织的影响

以ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ合金作为基体合金，添加少量Ａ１以研究其对ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ硬质合金的性能和组织的影响。结果发现：Ａ１可以细化合金中的ＷＣ晶粒，并在提高合金硬度的同时，使其抗弯强度提高１００～２００ＭＰａ。金相研究表明，添加Ａ１的ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ合金中的粘结相主要是γ相和板条马氏体，局部有α＋（Ｆ，Ｍｅ）＿３Ｃ的片层状组织存在。     

少量Al对WC—13?／Co／Ni硬质合金性能的组织的影响

以ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ合金作为基体合金，添加少量Ａｌ以研究其对ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ硬质合金的性能和组织的影响，结果发现，Ａｌ可以细化合金中的ＷＣ晶粒，并在提高合金硬度的同时，使其抗弯强度提高１００～２００ＭＰａ，金相研究表明，添加Ａｌ的ＷＣ－１３％Ｆｅ／Ｃｏ／Ｎｉ合金中的粘结相主要是γ相和板条马氏体，局部有α＋（Ｆｅ，Ｍｅ）３Ｃ的片层状组织存在。     

超音速喷涂WC－Co／45~＃钢的剪切强度及断口分析

测定了超音速喷涂ＷＣ－Ｃｏ／４５＃（或弹黄钢）的界面剪切强度。断口分析表明剪切断裂发生在４５＃钢基体和涂层的界面上。ＷＣ－Ｃｏ涂层主要由细小的ＷＣ相、块状含铁相和分布均匀的钴相组成。在ＷＣ－Ｃｏ／４５＃钢界面层中，块状含铁相是α－Ｆｅ和马氏体。马氏体的形成是ＷＣ中脱出的碳与铁结合形成的奥氏体再空冷的结果     

敏化型304不锈钢在约100℃硫酸钠溶液中的晶间应力腐蚀断裂

用板材拉伸试样在５０－１２５℃０．０１ＭＮａ２ＳＯ４溶液中研究了恒载荷、低应变速率下敏化型３０４（ＵＮＳ２３０４００）不锈钢的晶间应力腐蚀断裂（ＩＧＳＣＣ）敏感性。在１２５℃，晶间应力腐蚀断裂的敏感性主要处于钝化区的中部，ＩＧＳＣＣ的临界电位（Ｅｃｒｉｔ）接近于钝化电位，这与以前在１５０℃下的试验结果一致。但在７５℃和１００℃，ＩＧＳＣＣ却存在于活化到钝化的过渡电位区域内。在钝化电位以上，迟管测试     

稀土强化硬质合金的机理研究进展

探讨了稀土元素强化ＷＣ－Ｃｏ和ＷＣ－ＴｉＣ－Ｃｏ硬质合金的机理，认为稀土元素对钴粘结相的强化作用主要包括：抑制α－Ｃｏ→ε－Ｃｏ马氏体相变；固溶强化（一方面是钴粘相固溶微量的稀土元素，另一方面是稀土元素作用下钴粘结相中的Ｗ、Ｔｉ固溶含量提高）；改善钴粘结相对碳化物相的润湿性。稀土元素对ＷＣ－ＴｉＣ固溶体的强化是以质点强化机制为主，对ＷＣ相无明显强化作用，对合金的组织强化作用尚无定论。     

超音速喷涂WC—Co／45^#钢的剪切强度及断口分析

测定了超音速喷涂ＷＣ－Ｃｏ／４５＾＃的界面剪切强度。断口分析表明剪切断裂发生在４５＾＃钢基体和涂层的界面上。ＷＣ－Ｃｏ涂层主要由细小的ＷＣ相，块状含铁相和分布均匀的钴相组成。     

铁基阻尼合金的阻尼特性与磁性

使用共振法和日本３２５７型直流磁滞回线描绘仪，分别研究了铁基１２ＣｒＡｌＭｏＣ阻尼合金的应变振幅对阻尼本领Ｑ－１值的影响，以及碳含量对Ｑ＾－＾１值的影响，以及碳含量对Ｑ＾－＾１值，磁滞损耗能Ｗ，剩磁Ｂｒ，磁感Ｂ１０（１０Ａ／ｃｍ场强下的磁通）和矫顽力Ｈｃ的影响。结果表明，在采用的应变振幅范围内，随振幅加大，Ｑ＾－＾１值增大约７０％－１００％；碳含量从０．００２％增加至０．０２６％，Ｑ＾－＾１值减小     

Au/Ni/Al/Ti/AlxGa1-xN/GaN和Au/Pt/Al/Ti/AlxGa1-xN/GaN欧姆接触研究

研究并对比了Ti/Al/Ni/Au和Ti/Al/Pt/Au多层金属膜与未掺杂的Al0 .2 2 Ga0 .78N/GaN(i AlGaN/GaN)异质结构之间的欧姆接触性质。在退火温度低于 70 0℃时 ,两种接触样品上都不能得到欧姆接触。随着退火温度的升高 ,85 0℃快速退火后 ,在Ti/Al/Ni/Au接触上获得了 1.2 6×10 - 6 Ω·cm2 的比接触电阻率 ,在Ti/Al/Pt/Au接触上获得了 1.97× 10 - 5Ω·cm2 的比接触电阻率。研究结果表明 ,金属与半导体接触界面和Al0 .2 2 Ga0 .78N异质结构界面载流子沟道之间适当的势垒的存在对高质量欧姆接触的形成起重要作用 ,势垒的宽度取决于退火温度以及退火的具体进程。对Ti/Al/Ni/Au和Ti/Al/Pt/Au欧姆接触比接触电阻率的差异进行了解释。     

Effect of metal doping into Ce0.5Zr0.5O2 on catalytic activity of MnOx/Ce0.5–xZr0.5–xM0.2xOy/Al2O3 for benzene combustion

The research investigated the effect of doping two metals separately or together into Ce0.5Zr0.5O2 on the catalytic activity of MnOx/Ce0.5-xZr0.5-xM0.2xOy/Al2O3 （M=Y, Mn, Y and Mn） for catalytic combustion of benzene. The prepared catalysts were characterized by X-ray diffraction （XRD）, surface area analysis, oxygen storage capacity （OSC）, and H2-temperature programmed reduction （H2-TPR）. Catalytic test was performed on a conventional fixed bed flow reactor. The characterization results revealed that Y and Mn ions entered into the ceria-zirconia mixed oxides framework, which improved the textural properties and greatly promoted the MnOx dispersion on the support surface. The complete conversion temperature of benzene on MnOx/Ce0.4Zr0.4Y0.1Mn0.1Oy/Al2O3 was 563 K, and the selectivity of carbon dioxides was 99%. This catalyst could be applied in a wide range of GHSV and wide concentration condition, showing great potential for application.     

Superconducting Transition Temperature in YBa2Cu4O8/La2/3 Ca1/3 MnO3 / YBa2 Cu4O8 Heterostructure

YBa2Cu4O8/La2/3 Ca1/3 MnO3/YBa2Cu4O8 （ Y-124/LCMO/Y- 124） heterostructure was prepared by facing-target sputtering technique. The oscillatory superconducting transition temperature was observed when the thickness of LCMO d L is larger than critical thickness d L^CR. The metal-insulator transition temperature can only be detected at d L 〉 d L^CR. The dependence on the spacer layer in LCMO/Y-124 systems suggests strongly the interplay of ferromagnetic and superconducting couplings.     

锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2研究进展

介绍了比容量高、循环性能优异、成本较低的LiNil/3Co1/3Mnl/3O2正极材料近年来在合成技术及其掺杂改性、表面修饰等方面所取得的成果和进展,并对其未来的发展趋势进行了展望。     

热压烧结制备Li3/8Sr7/16Ta3/4Hf1/4O3钙钛矿型固体电解质

采用热压烧结制备了Li_3/8Sr_7/16Ta_3/4Hf_1/4O₃钙钛矿型固体电解质, 研究了不同烧结方式对样品性能的影响。通过X射线衍射仪表征材料的晶体结构, 扫描电子显微镜观察组织形貌, 交流阻抗仪测试电化学性能。结果表明:样品为立方KTaO₃相, 热压烧结成功合成了钙钛矿结构固体电解质, 相对于常压烧结, 热压烧结制备的样品孔隙更少, 晶粒之间结合更加紧密, 致密度高达94.0%, 离子电导率为4.33×10-4S·cm(T=298K).      

LiNi1/3Co1/3Mn1/3O2正极材料的合成与性能

采用共沉淀-高温固相法制备LiNi_1/3Mn_1/3Co_1/3O₂正极材料,利用XRD和SEM对所制试样的晶体结构和形貌进行表征,研究了烧结温度对材料电化学性能的影响.结果表明,焙烧温度为850 ℃制备的材料具有较好电化学性能,在25 ℃,电压范围为2.75~4.2 V,1 C充电6 C放电下首次放电比容量为124.2 mAh/g,50次循环后容量保持率为95.2 %.      

Effect of Zn Doping on Transport Properties of La2/3 Sr1/3 Mn1 - x Znx O3 Films

La2/3 Sr1/3 Mn1-x ZnxO3films （x =0.05, 0.1,0.3, and 0.5） were prepared using magnetron sputtering method, and the effect of Zn doping on transport properties of the films was studied. An analysis of X-ray diffraction showed that the main phase of the bulk target was orthorhombic and the films had better epitaxial character. It was found that the films with x =0.05 and x =0.1 exhibited typical insulator-metal transition. No transition of the films with x≥0.3 was observed and the dominant transport was variable-range hopping due to observable secondary phase ZnO. These could be attributed to the Zn doping effect on manganites.     

Catalytic combustion of diesel soot over K2NiF4-type oxides La2-xKxCuO4

Nanostructure K2NiF4 type oxides La2-xKxCuO4 complex oxides were prepared using the Sol-Gel method, characterized by X-Ray Diffraction （XRD）, Fourier Transform Infrared （FT-IR）, and Scanning Electron Microscopy （SEM）. The catalytic activity for soot combustion was evaluated by the Temperature-Programmed Reaction （TPO） technique. The results demonstrated that the substitution quality of K^＋ for La^3＋ at the A-site would increase the catalytic activities of La2-xKxCuO4 for soot combustion greatly; the substitution quality affected the structure and catalytic activity obviously. The La1.8K0.2CuO4 complex oxides with tetrahedral structures had the best catalytic activity for soot combustion, and the ignition temperature of soot combustion was lowered from 490 to 320 ℃.     

Crystal Structures and Thermoelectric Properties of Sm-Filled Skutterudite Compounds Smy Fex Co4 - x Sb12

Polycrystalline samples of Sm partially filled skutterudites SmyFexCo4-xSb12 were prepared by melting and Spark Plasma Sintering technique. The results of Rietveld refinement showed that the obtained SmyFexCo4-xSb12 samples possessed filled skutterudite structures. The thermal parameter （B） of Sm is larger than that of Sb, Fe, and Co, indicating that Sm ＂rattled＂ in Sb-icosahedron voids. The effects of filling atom Sm on thermoelectric properties of these compounds were investigated. With the increase of Sm filling fraction （y）, electrical conductivity decreased, Seebeck coefficient increased and had a maximum value when y was 0.38; thermal conductivity reduced and had a minimum value when y was 0. 32. At 750 K, the highest figure of merit of 0.68 was obtained for Sm0.32Fe1.47Co2.53Sb12.     

锂过量对钙钛矿型Li3/8Sr7/16Ta3/4Hf1/4O3固体电解质性能的影响

固相烧结法合成钙钛矿型Li_3/8Sr_7/16Ta_3/4Hf_1/4O₃(LSTH) 固体电解质材料,制备过程中分别加入过量的碳酸锂,质量分数分别为(0~30 %).通过XRD、SEM、ICP-OES以及EIS测试,表征不同锂过量LSTH固体电解质材料成相、显微形貌以及室温电导率的影响.实验结果表明,配料时,过量一定质量百分数的碳酸锂,能够有效减少烧结过程中因锂挥发而生成的SrTa₂O₆杂相,提高样品密度和室温电导率.样品最佳锂过量质量百分数为20 %,20 %锂过量样品1 300 ℃烧结10 h为钙钛矿纯相,密度6.5 g/cm3,室温电导率达到3.12×10-4 S/cm.