Ⅰ型载荷下缺口前端氢浓度分布的研究

采用离子探针微分析仪,对Ⅰ型载荷下21Cr9Ni9MnN奥氏体钢缺口前端氢浓度分布进行了研究。结果表明,缺口前端存在两个氢浓度的富集峰,一个位于缺口顶端,另一个距缺口稍远。缺口顶端的氢富集峰是位错对氢陷阱作用结果,而静水应力导致远离缺口的氢富集峰。对缺口前端氢的富集过程以及应力强度因子对氢浓度分布的影响进行了讨论。     

Roman glazed inkwells from the “Nuovo Mercato di Testaccio” (Rome,Italy): Production technology

This study is focused on Roman lead-glazed inkwells from the archaeological site of the “Nuovo Mercato di Testaccio” (Rome, Italy) dated in the half 2nd century AD. Optical microscopy (OM), X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and electron microprobe analysis (EMPA) have been used. Petrographic analysis of the body indicated the occurrence of only one fabric. The reaction zone at the contact glaze/body is marked by the enucleating of euhedral Pb-bearing alkali feldspar from a felsic melt enriched in Pb as revealed by EMP analysis. The mineralogical assemblages of the body and glaze, the microstructure and the chemical composition suggest that the inkwells were fired in the range 950–1100 °C, under oxidizing conditions.     

离子微探针研究氢在材料中行为的新进展

本文阐述了我们近年来利用离子微探针对氢在材料中的基本行为研究取得的若干新进展:(1) 在裂纹尖端氢分布研究方面有突破性进展,首次实验发现在受载裂纹尖端存在着氢富集的双峰,对氢双峰的变化规律和形成原因进行了系统研究,并提出了相应的模型;(2) 实验确证了氢在六角密堆结构(hcp)和高位错密度(10~(12)/cm~2)材料塑性形变过程中的可动位错输运行为,并揭示了氢在位错芯部的“隧道扩散效应”;(3) 定量测定了工程厚度材料微区氢浓度分布,通过Fourier变换和Laplace变换,建立了新的微区氢扩散方程解析式,具有重要的实用价值。     

一种基于实时数字图像处理的同步辐射微探针自动化扫描新方法

在上海光源硬X微聚焦及应用光束线站(BL15U1)上实现了一种基于实时数字图像处理的同步辐射微探针自动化扫描方法。该方法采用高灵敏度、高帧率的数字电荷耦合器件(Charge Coupled Device,CCD)显微镜实时成像,通过对显微镜系统和X光微米探针系统的坐标转换,使用户在图像空间直接点击到感兴趣的位置后,样品台就自动将该点移入光路。在设定好扫描时间、扫描步长等必要的实验参数后,只需要用鼠标在图像空间圈出需要扫描的区域,系统将自动生成XPS运动控制器的运动配置文件,并驱动电机运动,对该区域进行微束荧光扫描成像。结果表明,该方法不仅可以提高同步辐射机时的使用效率,而且可以满足微区研究人员快捷、方便的自动化操作需求。     

Ti和Cu对C/Al复合材料界面反应的影响

在文献[1]所建立的C/Al复合材料界面反应动力学的基础上,利用扫描俄歇微探针深度分析测量了不同退火工艺的模拟C/Al-Ti和C/Al-Cu样品界面反应层的厚度,求得相应的界面反应激活能,并确定了界面反应从慢到快的顺序为C/Al-Ti、C/Al-Cu和C/Al。      

Precision friction measurement between ultrathin wire and microprobe

In this study, using an experimental technique based on small-span bending, the friction behaviors of ultrathin Pt wires with the tungsten microprobes have been reported. In the technique, friction force for sliding of a simply supported wire under bending load applied by closely positioned two opposite probes is measured by a microforce sensor. The force sensor is a capacitive detection type double-beam passive cantilever. Specificity of the microforce sensor provides the technological advantage for precise measurement of friction and normal contact forces sequentially under the observation by a high-resolution digital microscope. Static and kinetic frictions due to externally applied force, internal adhesive force and relative motion are successfully determined. Furthermore, the measured friction in wire-probe contact is used in the determination of the mechanical properties of the wire material.     

微探针法测定“北京烤鸭”皮下导热系数的研究

采用非稳态微探针法测定“北京烤鸭”皮下导热系数。结果显示,鸭坯皮下含水率为6.55%～14.2时,导热系数值在0.1178W/(m·K)～0.1973W/(m·K)之间变化,且呈线性相关趋势。     

力学探针在材料选区力学性能测量上的应用

介绍了力学探针的工作原理，并通过对不同应力状态下弹簧钢力学性能和TiN硬质薄膜力学性能的测量实例，展示了力学探针技术在材料选区力学性能评价上所具有的明显优势和广阔的应用前景。     

Ti和Cu对C/Al复合材料界面反应的影响

在文献[1]所建立的C/Al复合材料界面反应动力学的基础上,利用扫描俄歇微探针深度分析测量了不同退火工艺的模拟C/Al-Ti和C/Al-Cu样品界面反应层的厚度,求得相应的界面反应激活能,并确定了界面反应从慢到快的顺序为C/Al-Ti、C/Al-Cu和C/Al。     

Advances in elemental imaging of rocks using the AGLAE external microbeam

Rocks are widely represented in cultural heritage materials. They constitute the major part of archaeological artefacts like stone carvings, tools and weapons, and are present in art works in various forms, such as precious stone inlays or paint pigments. The study of such geomaterials, which are usually constituted of a complex aggregate of mineral phases, aims at determining their exact nature, their provenance and at understanding their possible alteration. Since minerals are often composed of light elements, IBA techniques such as PIXE and PIGE, thanks to their ability to measure with high sensitivity elements down to lithium, should be well adapted to their analysis. However, the bulk composition classically obtained using macro-IBA on pelletized samples or using a broad beam hides the multi-phased nature of the rocks and considerably blurs the searched chemical fingerprint. In contrast, the small size of a nuclear microprobe allows imaging the chemical composition at a finer scale and, when implemented in air, appears ideally suited to analyse without sampling these often precious items. This paper illustrates chemical micro-imaging of rocks with examples performed with the AGLAE external nuclear microprobe: characterisation of microscopic inclusions in gems and detailed chemical mapping of rocks with special emphasis to lapis lazuli. Lapis lazuli is of particular interest in both archaeology and art history: after being employed in Asia since the 7th millennium BC to make carvings and beads, it was used in Medieval Europe as a precious blue painting pigment known as ultramarine. The chemical imaging of major and trace elements in lapis lazuli using external μ-PIXE has permitted to identify its mineral phases, to assign their trace elements and to evidence undetected elements. In combination with μ-XRD and μ-Raman spectrometry, this approach provides a clear mineralogical fingerprint useful to determine rock provenance and to authenticate artefacts of unknown origin. These encouraging results call for the generalization of this non-destructive approach to the study of other heterogeneous materials in art and archaeology.