High Precision Microscale Bending by Pulsed and CW Lasers

2003 ◽  
Vol 125 (3) ◽  
pp. 512-518 ◽  
Author(s):  
X. Richard Zhang ◽  
Xianfan Xu

This paper discusses high precision microscale laser bending and the thermomechanical phenomena involved. The use of a pulsed and a CW laser for microscale bending of ceramics, silicon, and stainless steel is demonstrated. For each laser, experiments are conducted to find out the relation between bending angles and laser operation parameters. Changes of the ceramics surface composition after laser irradiation are analyzed using an electron probe microanalyzer (EPMA). Results obtained by the pulsed and the CW laser are compared, and it is found that the CW laser produces more bending than the pulsed laser does. However, the pulsed laser causes much less surface composition change and thermomechanical damage to the targets. Numerical calculations based on the thermo-elasto-plastic theory are carried out and the results are used to explain the phenomena observed experimentally.

2001 ◽  
Author(s):  
X. Richard Zhang ◽  
Xianfan Xu

Abstract This paper presents the technique of high precision microscale laser bending and the study of the thermomechanical phenomena involved. The use of pulsed and CW lasers for microscale bending of ceramics, silicon, and stainless steel is demonstrated. Experimental studies are conducted to find out the relation between bending angles and laser operation parameters. Bending results obtained by a pulsed and a CW laser are compared. Changes of surface composition after laser irradiation are analyzed. Numerical calculations based on thermo-elasto-plastic theory are conducted and results are compared with the experimental data Examples of industrial applications of high precision laser bending are given.


1965 ◽  
Vol 9 ◽  
pp. 487-503
Author(s):  
A. K. Baird ◽  
D. H. Zenger

AbstractThe major elements m common rocks are of low atomic number, but analyses of high precision are possible by soft X-ray spectrography if several grams of rock sample are available. The electron-probe microanalyzer is shown to complement this established method by permitting analyses of particles as small as 1 μ in diameter. This paper describes applications of these methods to the analysis of the major and minor elements of silicate, carbonate, and phosphate minerals and rocks.Elements of particular interest are as follows : carbon in particles enclosed in carbonate rocks; oxygen, as the major constituent of the specimens; phosphorus in phosphatic nodules and apatites; manganese and iron, as colorations in fossil shells; and the group oxygen, sodium, magnesium, aluminum, silicon, potassium, calcium, and iron as complex segregations and zonations within single crystals of several mineral phases.If the bulk composition of a rock is known, and also the chemistry of the constituent minerals, it is possible to compute quantitative minéralogie analyses of high precision. Thus, the combined use of soft X-ray spectrography and electronprobe microanalysis can provide quantitative chemical and mineralogicat information on the earth's crust on all scales from thousands of square miles (by means of appropriate sampling) down to the scale of 1 μ.


Author(s):  
G.F. Bastin ◽  
H.J.M. Heijligers

Among the ultra-light elements B, C, N, and O nitrogen is the most difficult element to deal with in the electron probe microanalyzer. This is mainly caused by the severe absorption that N-Kα radiation suffers in carbon which is abundantly present in the detection system (lead-stearate crystal, carbonaceous counter window). As a result the peak-to-background ratios for N-Kα measured with a conventional lead-stearate crystal can attain values well below unity in many binary nitrides . An additional complication can be caused by the presence of interfering higher-order reflections from the metal partner in the nitride specimen; notorious examples are elements such as Zr and Nb. In nitrides containing these elements is is virtually impossible to carry out an accurate background subtraction which becomes increasingly important with lower and lower peak-to-background ratios. The use of a synthetic multilayer crystal such as W/Si (2d-spacing 59.8 Å) can bring significant improvements in terms of both higher peak count rates as well as a strong suppression of higher-order reflections.


1999 ◽  
Vol 5 (S2) ◽  
pp. 78-79
Author(s):  
C. Merlet ◽  
X. Llovet ◽  
F. Salvat

Studies of x-ray emission from thin films on substrates using an electron probe microanalyzer (EPMA) provide useful information on the characteristics of x-ray generation by electron beams. In this study, EPMA measurements of multilayered samples were performed in order to test and improve analytical and numerical models used for quantitative EPMA. These models provide relatively accurate results for samples consisting of layers with similar average atomic numbers, because of their similar properties regarding electron transport and x-ray generation. On the contrary, these models find difficulties to describe the process when the various layers have very different atomic numbers. In a previous work, we studied the surface ionization of thin copper films of various thicknesses deposited on substrates with very different atomic numbers. In the present communication, the study is extended to the case of multilayered specimens.The studied specimens consisted of thin copper films deposited on a carbon layer which, in turn, was placed on a variety of single-element substrates, ranging from Be to Bi.


2009 ◽  
Vol 24 (8) ◽  
pp. 2638-2643 ◽  
Author(s):  
Kai-Jheng Wang ◽  
Yan-Zuo Tsai ◽  
Jenq-Gong Duh ◽  
Toung-Yi Shih

An Sn-patch formed in Ni(V)-based under bump metallization during reflow and aging. To elucidate the evolution of the Sn-patch, the detailed compositions and microstructure in Sn–Ag–Cu and Ti/Ni(V)/Cu joints were analyzed by a field emission electron probe microanalyzer (EPMA) and transmission electron microscope (TEM), respectively. There existed a concentration redistribution in the Sn-patch, and its microstructure also varied with aging. The Sn-patch consisted of crystalline Ni and an amorphous Sn-rich phase after reflow, whereas V2Sn3 formed with amorphous an Sn-rich phase during aging. A possible formation mechanism of the Sn-patch was proposed.


1982 ◽  
Vol 87 (6) ◽  
pp. 317-320 ◽  
Author(s):  
A. Miotello ◽  
L.F. Donàdalle Rose

2010 ◽  
Vol 160-162 ◽  
pp. 1787-1790
Author(s):  
Jing Cao ◽  
Yong Feng Wang ◽  
Chun Xue Wei

1J79 alloy was prepared by vacuum electric arc smelting.The crystal growth and the content of impurity was observed by electron probe microanalyzer,and magnetic properties were measured by vibrating sample magnetometer(VSM).Experimental results show that inclusions in the alloy are fewer and fewer, composition becomes more uniform with the increases of the Mo content, and grain size also becomes larger and larger with the increases of Mo content, to reduce coercivity. The small amount of Mo addition is useful to improve the saturation magnetization and reduce coercivity.


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