高温合金活性剂激光微焊接接头的组织性能研究（英文）

采用配方均匀设计法,配制了SiO2-MnO2-CaO-TiO2-CaF2-NaF多组元活性剂,利用微型脉冲激光器对500μm厚GH4169高温合金进行了活性剂激光焊接试验。分析并讨论了焊接接头的显微组织和力学性能。试验结果表明,与传统激光焊相比,所配制的20种活性剂均增加了焊缝熔深,并且其中F12系混合活性剂增加熔深能力最为显著,使焊缝深宽比增加了159%,证明通过使用活性剂来增加微激光焊焊缝熔深,降低高温合金板激光焊接的成本是可行的。在活性剂作用下,焊缝显微组织仍由柱状晶和等轴晶组成,接头抗拉强度达到927 MPa,为母材强度的92.7%。     

Surface defects,stress evolution,and laser damage enhancement mechanism of fused silica under oxygen-enriched condition

Oxygen ions (O⁺) were implanted into fused silica at a fixed fluence of 1×10¹⁷ ions/cm² with different ion energies ranging from 10 keV to 60 keV. The surface roughness, optical properties, mechanical properties and laser damage performance of fused silica were investigated to understand the effect of oxygen ion implantation on laser damage resistance of fused silica. The ion implantation accompanied with sputtering effect can passivate the sub-/surface defects to reduce the surface roughness and improve the surface quality slightly. The implanted oxygen ions can combine with the structural defects (ODCs and E' centers) to reduce the defect densities and compensate the loss of oxygen in fused silica surface under laser irradiation. Furthermore, oxygen ion implantation can reduce the Si-O-Si bond angle and densify the surface structure, thus introducing compressive stress in the surface to strengthen the surface of fused silica. Therefore, the laser induced damage threshold of fused silica increases and the damage growth coefficient decreases when ion energy up to 30 keV. However, at higher ion energy, the sputtering effect is weakened and implantation becomes dominant, which leads to the surface roughness increase slightly. In addition, excessive energy aggravates the breaking of Si-O bonds. At the same time, the density of structural defects increases and the compressive stress decreases. These will degrade the laser laser-damage resistance of fused silica. The results indicate that oxygen ion implantation with appropriate ion energy is helpful to improve the damage resistance capability of fused silica components.     

The effect of Si content on the martensitic transfor-mation temperature of Ni55.5e18Ga26.5-xSix alloys

This paper investigates the effects of substitution of Si for Ga on the martensitic transformation behaviours in Ni-Fe-Ga alloys by using optical metallographic microscope and differential scanning calorimetry (DSC) methods. The structure type of Ni_55.5Fe₁₈Ga_26.5-xSi_x alloys is determined by x-ray diffraction (XRD), and the XRD patterns show the microstructure of Ni-Fe-Ga-Si alloys transformed from body-centred tetragonal martensite (with Si content x = 0) to body-centred cubic austenite (with x = 2) at room temperature. The martensitic transformation temperatures of the Ni_55.5Fe₁₈Ga_26.5-xSi_x alloys decrease almost linearly with increasing Si content in the Si content range of x ≤ 3. Thermal treatment also plays an important role on martensitic transformation temperatures in the Ni-Fe-Ga-Si alloy. The valence electronic concentrations, size factor, L2₁ degree of order and strength of parent phase influence the martensitic transformation temperatures of the Ni-Fe-Ga-Si alloys. An understanding of the relationship between martensitic transformation temperatures and Si content will be significant for designing an appropriate Ni-Fe-Ga-Si alloy for a specific application at a given temperature.     

Bright blue photoluminescence from a mixed tin and manganese oxide xerogel prepared via solben hydrothermalben gel process

A new blue photoluminescent material, a mixed tin and manganese oxide xerogel, is prepared via sol-hydrothermal-gel process assisted by citric acid. The composition xerogel exhibits strong blue emission at room temperature, with an emission maximum at 434 nm under short (234 nm) or long-wavelength (343 nm) ultraviolet excitation. The photoluminescent excitation spectrum of the mixed tin and manganese oxide xerogel, monitored at an intensity maximum wavelength of 434 nm of the emission, consists of two excitation peaks at 234 nm and 343 nm. With heat treatment temperature increasing from 110 ℃ to 200 ℃, the blue emission intensity increases remarkably, whereas it is almost completely quenched after being treated at 300 ℃. The carbon impurities in the mixed tin and manganese oxide xerogel, confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, should be responsible for the bright blue photoluminescence.     

等温退火对辐照诱发的非晶TiNiCu合金微观组织结构的影响

 TiNiCu记忆合金在美国Argonne国家实验室IVEM Tandem National Facility加速器产生的400keV Xe+离子辐照到0.4dpa时发生非晶化转变。通过电子显微镜研究了非晶化的TiNiCu合金的回复和再结晶过程。退火加热的速度是10℃/min。在280℃时非晶环附近出现电子衍射斑点以及明场像中出现少量析出相，表明回复和再结晶开始。退火到550℃出现多晶环，650℃时有片状马氏体变体生成，750℃时有很锐利的多晶环出现，表明再结晶过程基本完成。经标定再结晶晶粒仍然是TiNiCu记忆合金。再结晶组织与辐照前TiNiCu 合金的显微组织相比有较大差异。     

18 MeV质子辐照对TiNi形状记忆合金R相变的影响

 研究了用HZ-B串列加速器的18MeV质子辐照对TiNi形状记忆合金R相变的影响，辐照在奥氏体母相状态下进行。示差扫描量热法（DSC）表明，辐照后R相变开始温度T^s_R和逆马氏体相变结束温度T^f_A随辐照注量的增加而降低。当注量为1.53×10¹⁴/cm²时，T^sR和T^f_A分别下降6K和13K，辐照未引起R相变结束温度T^s_R和逆马氏体相变开始温度T^f_A的变化。表明辐照后母相(奥氏体相)稳定。透射电镜（TEM）分析表明辐照后没有引起合金可观察的微观组织变化。辐照对R相变开始温度T^s_{R和逆马氏体相变结束温度Af的影响可能是由于质子辐照后产生了孤立的缺陷团，形成了局部应力场，引起晶格有序度的下降所造成的。}     

表面热透镜技术测试光学薄膜特性研究

在薄膜特性的研究工作中，激光引起的表面形变是一种广泛应用的技术。在这种技术中，薄膜的形变(热包高度小于0．1nm)一般是采用光热偏转技术来探测的。介绍了一种通过光学衍射效应来研究薄膜表面形变的新技术即表面热透镜技术，它是研究薄膜特性的一种灵敏且易于控制的方法。探讨了其理论模型及在薄膜的吸收测量和缺陷特性测试方面，该方法相对于传统方法的优点和潜力。     

ICF装置靶场关键材料的辐照效应研究进展

从惯性约束聚变（ICF）装置中靶场关键材料易受辐照损伤、从而限制材料使用寿命和装置稳定运行的现实问题出发,总结归纳了有关不锈钢、铝合金、终端光学组件三大类靶场关键材料的辐照效应研究进展,详细介绍了靶室内高能中子束、γ射线、X射线等高能粒子和射线引起靶室第一壁材料出现烧蚀、中子活化等辐照损伤问题,以及靶室环境对关键材料的影响和防护处理。此外,还阐述了打靶试验中所产生的复杂辐射环境、基频与三倍频激光对靠近靶室的终端光学组件所产生的各类辐照损伤现象和相关作用机理。     

R.C.Hibbeler编著《Mechanics of Materials》(5th Edition)评介

R．C．Hibbeler编著《材料力学》（第5版）（《Mechanics of Materials》，Prenties Hall，2003）已于2004年1月由高等教育出版社出版了影印版．该书是一本优秀教材，其内容与我国当前高等学校工科本科材料力学课程的教学要求也相当接近，对我国的材料力学教材建设和双语教学具有极大参考价值．     

含氟聚甲基丙烯酸酯/聚异丁烯嵌段共聚物的成膜性质研究

利用氧负离子聚合方法制备含氟聚异丁烯三嵌段共聚物,聚异丁烯-b-聚甲基丙烯酸-2-(N,N-二甲氨基)乙酯-b-聚甲基丙烯酸-(2,2,3,3,4,4,5,5-八氟)戊酯(PIB-b-PDMAEMA-b-POFPMA),对PIB60-bPDMAEMA63-b-POFPMA11的物理化学性质和成膜性能进行了研究.利用1H-NMR和GPC表征了聚合物的化学结构、分子量及分子量分布;通过TGA和DSC测试了聚合物的热分解温度与玻璃化转变温度(Tg).实验结果表明,PIB60以及PDMAEMA63的Tg分别为-61℃和5℃,PIB60-b-PDMAEMA63在-4℃左右存在一个Tg,而PIB60-b-PDMAEMA63-b-POFPMA11不仅在-4℃存在玻璃化转变,而且在26℃存在另一个玻璃化转变,对应于POFPMA嵌段的Tg.将聚合物制成薄膜,通过接触角测试发现聚合物薄膜具有一定的疏水疏油性质.根据Owens-Wendt公式计算了聚合物薄膜的自由能、分散能和极性能.利用原子力显微镜(AFM)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和X射线衍射分析(XRD)研究了聚合物中含氟嵌段向薄膜表面迁移富集和堆积结构,结果显示,在退火之后,含氟嵌段向薄膜的表面迁移、富集,并在表面排列形成双层堆积结构.