温拌胶粉改性沥青低温性能及其与集料黏附性分析

通过弯曲梁流变(BBR)试验、接触角测量及原子力显微镜(AFM)测试等方法,从宏观和微观角度对老化前后温拌胶粉改性沥青(WCR)低温抗裂性及其与集料黏附性的变化规律进行研究,并以热拌胶粉改性沥青(HCR)作为对比。结果表明:随着老化程度的加深,HCR、WCR的蠕变速率(m)和弯曲蠕变劲度(S)的比值(m/S)减小,低温抗裂性能变差,WCR的低温抗裂、抗老化性能均优于HCR;老化前后HCR、WCR与三种集料的黏附性能大小依次为石灰岩＞玄武岩＞花岗岩,WCR与集料的黏附性均优于HCR;老化前后两种沥青的微观Derjaguin-Muller-Toporov(DMT)模量与低温流变参数(m/S)呈良好线性关系,且基于Johnson-Kendall-Roberts(JKR)力学模型得到的微观表面能、黏附功分别与基于表面能理论得到的宏观表面能、黏附功呈较强相关性。     

蒙砂粉熟化过程与蚀刻玻璃表面的研究

固体蒙砂粉的熟化质量是决定玻璃蚀刻效果的重要因素。用X射线衍射（XRD）、能谱仪（EDS）、拉曼光谱、粘度计、Zeta电位和碱滴定等方法研究了用柠檬酸和氟化氢铵为主要成分配制的蒙砂粉的理化性质随熟化时间的变化规律,考察和评价了熟化时间对GG6手机盖板玻璃蚀刻效果的影响。结果表明：熟化时间为36 h,得到的熟化液的黏度和氢离子浓度最大,GG6玻璃蚀刻后的粗糙度为265 nm、雾度为84%、透光率为92.4%、光泽度为11.7%,符合工业上手机玻璃盖板的蚀刻加工质量要求,蚀刻后的GG6玻璃表面形成一层微量的氟硅酸物晶体,构成的微纳蚀孔结构更均匀。测定蒙砂液的理化性质能有助于更好地了解蒙砂粉的熟化过程,对蒙砂粉蚀刻工艺具有指导作用,提高玻璃防眩工艺的生产效率。     

现场老化对沥青胶结料性能的影响

研究了沥青路面不同深度处沥青胶结料的老化程度.比较了现场老化沥青和室内老化沥青的流变性能,并评价了路面不同深度处老化沥青的流变性能.     

基于键合线等效电阻的IGBT模块老化失效研究

已有研究表明,键合线老化脱落失效是影响绝缘栅双极型晶体管(IGBT)可靠性的主要因素之一。以此为研究背景,首先根据IGBT模块内部键合线的结构布局与物理特性,分析键合线等效电阻与关断暂态波形的关系,建立键合线等效电阻与关断过程中密勒平台电压以及集电极电流的数学关系式,通过实验测量获得键合线等效电阻,最后分别对键合线等效电阻与键合线断裂数的关系进行定性与定量的分析,得出键合线等效电阻会随键合线断裂数的增加同方向变化,这也证明了本文所提方法的可行性和正确性。     

2:17型稀土钴永磁体磁饱和度对其不可逆损失的影响

采用亥姆霍兹线圈测试不同磁饱和度及工作点(P_c)的2:17型钐钴磁体温度老化前后的磁通,计算经温度老化后的不可逆损失,探讨了老化温度、永磁体磁饱和度及P_c对其不可逆损失的影响。结果表明,永磁体的不可逆损失随老化温度的升高、磁体磁饱和度的降低及P_c的降低而变大。不可逆损失绝对值小于1%时,老化温度为200℃,P_c=0.27的磁体磁饱和度需要超过53.6%,而P_c=1.78仅需超过31.5%,老化温度为300℃,P_c=0.27的磁体的磁饱和度需要超过88.6%,而P_c=1.78的磁体仅需超过68.1%。     

Understanding Electrical Performance and Microstructure of Water Tree Aged Cables after Silicone Injection during Electrical-Thermal Accelerated Aging

To further understand the long-term effect of rejuvenation fluid on water tree aged cross-linked polyethylene (XLPE) cables after silicone injection, electrical performance and microstructure of water tree aged cables were investigated during an electrical-thermal accelerated aging experiment. Two groups of treated and untreated water tree aged cable samples were subjected to electrical-thermal aging for 2 weeks. The results of the dielectric loss factor showed that the electrical performance of the treated samples was significantly better than that of untreated samples after electrical-thermal aging. Microobservation results showed that the overall water tree sizes of the treated samples were much smaller than those of the untreated samples after electrical-thermal aging. Furthermore, there was a second growth of water trees in the original water tree region during electrical-thermal aging in both groups of samples. Using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), rejuvenation fillers were observed tightly embedded in water tree voids after electrical-thermal aging. The infrared (IR) spectroscopy analysis results showed that the concentration of rejuvenation fluid increased from the outer layer to the inner layer of insulation. Based on the results, due to the improvement of the electric field at the water tree tip and the diffusion of silicone fluid in the insulation layer, both the second growth in the original water tree region and continuing growth at the water tree tip can be effectively inhibited.     

冷轧预变形量对1460合金组织和性能的影响

本文研究了时效前不同冷轧预变形量（ε=7%,14%,20%,27%）对1460合金沉淀强化过程的影响。当冷轧变形量增加至20%时,合金中出现位错墙（Dense Dislocation Wall）。位错为T1相提供了形核位置,使得合金中T1相的数量增加同时尺寸保持在100 nm 左右,缩短了时效峰值时间。27%冷轧变形+160 ℃/12 h时效能提高合金的强度,同时塑性较好,此时合金的抗拉强度和延伸率分别为590 MPa和8%。     

不同处理工艺对Cu-Ni-Co-Si合金组织与性能的影响

通过物理性能测试和采用扫面电子显微镜SEM、透射电子显微镜TEM、高分辨透射电子显微镜HRTEM等分析测试技术,系统研究不同处理工艺对Cu-Ni-Co-Si合金微观组织与性能的影响规律。研究结果表明,合金热轧在线淬火时效处理后,合金中存在大量的正交结构的大颗粒(Ni、Co)₂Si相和少量、细小的(Ni、Co)₂Si相,是导致合金综合性能无法满足后续使用的主要原因;经固溶时效和固溶冷变形时效处理后,合金的硬度与时效时间的关系曲线均呈单峰型,而合金的导电率与时效时间的关系曲线均呈先快速增加后缓慢增大最后趋于稳定的趋势;合金经固溶时效和固溶冷变形时效处理后,基体出现大量圆盘状的正交结构的(Ni、Co)₂Si相,与基体的取向关系为 。     

Mechanical Relaxation of a Ti_(36.2)Zr_(30.3)Cu_(8.3)Fe_4Be_(21.2) Bulk Metallic Glass: Experiments and Theoretical Analysis

The dynamic mechanical relaxation behavior of Ti_(36.2)Zr_(30.3)Cu_(8.3)Fe_4Be_(21.2) bulk metallic glass with good glass-forming ability was investigated by mechanical spectroscopy. The mechanical relaxation behavior was analyzed in the framework of quasi-point defects model. The experimental results demonstrate that the atomic mobility of the metallic glass is closely associated with the correlation factor χ. The physical aging below the glass transition temperature T g shows a non-Debye relaxation behavior, which could be well described by stretched Kohlrausch exponential equation. The Kohlrausch exponent β_(aging) reflects the dynamic heterogeneities of the metallic glass. Both concentration of "defects" and atomic mobility decrease caused by the in situ successive heating during the mechanical spectroscopy experiments.     

Ti-22Al-26Nb-1Zr 合金在长期时效过程中的组织稳定性

研究正交结构Ti?22Al?26Nb?1Zr合金片层组织在长期时效过程中B2相的分解、O相板条的球化等显微组织演变规律。结果表明：合金加热到B2单相区炉冷后可以获得板条组织,在(O+B2)相区700°C时效100 h以内显微组织无明显变化。但在长时时效过程中板条组织发生明显粗化。在700°C长期时效800 h时,B2相极不稳定,会在时效初期短时间内迅速发生分解。随着时效时间的延长,块状和少量板条状O相在晶界和O/BCC相界处析出并以球状形式长大。此外,在时效时间超过100 h后,会有明显的树枝状O相板条组织形成。