Laser Cutting of Small Diameter Holes Into Alumina Tiles: Thermal Stress Analysis

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
B. S. Yilbas ◽  
S. S. Akhtar ◽  
C. Karatas
Keyword(s):  
Residual Stress ◽  
Laser Cutting ◽  
Small Diameter ◽  
Optical Microscope ◽  
Stress Fields ◽  
Finite Element Code ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cut Surface ◽  
Scanning Electron

Laser cutting of small diameter holes in alumina tiles is carried out. Temperature and stress fields are predicted numerically using the ABAQUS finite element code. The cut sections are examined by incorporating scanning electron microscope and optical microscope. The residual stress developed in the cutting section is determined using the X-ray diffraction technique. It is found that high residual stresses are formed in the cutting section, and predictions agree well with the experimental results. The laser cut edges are found to be free from the large cracks. However, interconnected shallow cracks are observed at the hole cut surface.

Interaction between Two Ni-Base Alloys and Ceramic Moulds

2013 ◽  
Vol 747-748 ◽  
pp. 765-771 ◽  
Author(s):  
Jian Sheng Yao ◽  
Ding Zhong Tang ◽  
Xiao Guang Liu ◽  
Cheng Bo Xiao ◽  
Xin Li ◽  
...  
Keyword(s):  
Solid Solution ◽  
Interface Reaction ◽  
Vapour Phase ◽  
Optical Microscope ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Reaction Surfaces

The interfacial reactions between ceramic moulds and DZ417G and DZ125 superalloys were investigated. The microstructure and composition of the interface region were observed by optical microscope, X-ray diffraction and scanning electron microscope with energy dispersive spectroscopy. The results showed that (Al1-xCrx)2O3solid solution phase with pink color was formed from the dissolution of Cr2O3and Al2O3and vapour phase, which was transferred to the reaction surfaces. The reaction layer thicknesses of DZ417G and DZ125 alloys were about in the range of 40-50μm. The interface reaction product between DZ417G alloy and ceramic mould was TiO2and the product between DZ125 alloy and ceramic mould was HfO2.

X-Ray Diffraction Measurement of Residual Stresses in Thick, Multi-Pass Steel Weldments

1985 ◽  
Vol 107 (2) ◽  
pp. 185-191 ◽  
Author(s):  
C. O. Ruud ◽  
R. N. Pangborn ◽  
P. S. DiMascio ◽  
D. J. Snoha
Keyword(s):  
Residual Stress ◽  
Measurement Accuracy ◽  
Stress Measurement ◽  
Three Dimensional ◽  
Residual Stress Measurement ◽  
Stress Fields ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Technique

A unique X-ray diffraction instrument for residual stress measurement has been developed that provides for speed, ease of measurement, accuracy, and economy of surface stress measurement. Application of this instrument with a material removal technique, e.g., electropolishing, has facilitated detailed, high resolution studies of three-dimensional stress fields. This paper describes the instrumentation and techniques applied to conduct the residual stress measurement and presents maps of the residual stress data obtained for the surfaces of a heavy 2 1/4 Cr 1 Mo steel plate weldment.

scholarly journals Effect of CNT Contents on the Microstructure and Properties of CNT/TiMg Composites

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1620
Author(s):  
Xiaomin Yuan ◽  
Haonan Zhu ◽  
Huiling Ji ◽  
Yiwei Zhang
Keyword(s):  
Cross Section ◽  
Optical Microscope ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Wet Milling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure Observation ◽  
The Matrix ◽  
Scanning Electron

Carbon nanotubes (CNTs), dispersed in absolute ethanol, were evenly mixed into Ti/MgH2 powders by wet milling. Then, we applied the vacuum hot-pressed sinteringmethod to the CNTs/TiMg composite materials. An optical microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and a field emission scanning electron microscope (FESEM) were used for the microstructure observation and phase analysis of samples. The mechanical properties were measured via the micro-vickers hardness. The results show that the main phases in the composites were Ti, Mg and C. Meanwhile, a small amount of Ti-Mg solid solution phase was also found. The cross-section morphology of the composites shows that the melted magnesium fills the grain interface during extrusion and that the composites have a better compactness.The microstructures of the composites have been greatly refined as the CNT contents increased. The structure of the composites was further refined when 0.5 wt.% CNTs were added. The fracture surface is obviously a ductile fracture. The microhardness increases obviously with the CNT content increasing. When the content of the CNTs is 1.0 wt.%, the microhardness of the composites reaches 232 HV, which is 24% higher than that of the matrix.

A Simple Method for Controlling the Morphology of CuO Nanostructures by Droplet

2012 ◽  
Vol 535-537 ◽  
pp. 280-283 ◽  
Author(s):  
Hao Ran An ◽  
Feng Shi Cai ◽  
Xue Wei Wang ◽  
Zhi Hao Yuan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscope ◽  
Growth Mechanisms ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Hydrophobic Substrate ◽  
X Ray ◽  
Shape Selective ◽  
Scanning Electron

Different morphology CuO nanostructures, including platelets, flower-like were simply synthesized at 350 °C controlled by droplet on hydrophobic substrate. This is a simple method which does not require any template, catalyst, or surfactant but can control the morphology of CuO from platelets to flowerlike. The morphologies are strongly dependent on the volume of droplet. Scanning electron microscopy (SEM), Optical microscope and X-ray diffraction (XRD) were used to observe the morphology, crystallinity, and chemical composition of the CuO structures. Growth mechanisms for shape selective CuO synthesis were proposed based on these results.

Modification of Microstrucure and Residual Stress on Friction Welding Surface of Titanium Alloy by Water-Jet Cavitation Peening

2011 ◽  
Vol 317-319 ◽  
pp. 429-435 ◽  
Author(s):  
Dong Ying Ju ◽  
Xin Mao Fu ◽  
Shun Na ◽  
Bing Han ◽  
Xiao Hu Deng
Keyword(s):  
Electron Microscopy ◽  
Residual Stress ◽  
Welded Joints ◽  
Compressive Residual Stress ◽  
Welded Joint ◽  
Water Jet ◽  
X Ray Diffraction ◽  
X Ray ◽  
Welding Surface ◽  
Scanning Electron

Water jet cavitation peening is applied to improve the strength and mechanical properties of the friction-welded joints of titanium alloys. Scanning electron microscopy observations of the microstructure of the welded joints and welded area before/after water jet cavitation peening confirm slip dislocation at the microstructure near the surface of the specimens. The residual stress on the surface of the welded joint is measured by X-ray diffraction. The results indicate the effect of peening time on the strength of compressive residual stress.

scholarly journals Studying the Microstructure of Al-Ti Alloy Prepared by Powder Metallurgy using Three Different Percentages of Ti

2020 ◽  
Vol 26 (6) ◽  
pp. 132-139
Author(s):  
Sahib Mohammed Mahdi ◽  
Nadia Ghadhanfer Hikmat ◽  
Dalmn Yaseen Taha
Keyword(s):  
Electron Microscope ◽  
Powder Metallurgy ◽  
Optical Microscope ◽  
Ti Alloy ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alloy Properties ◽  
Ti Content ◽  
Scanning Electron

The effect of different Ti additions on the microstructure of Al-Ti alloy prepared by powder metallurgy was investigated. A certain amount of Ti (10wt%, 15wt%, and 20wt%) were added to aluminium and the tests like microhardness, density, scanning electron microscope (SEM), optical microscope (OM) and X-Ray Diffraction (XRD) were conducted to determine the influence of different Ti additives on the Al-Ti alloy properties and microstructure. The results show that the grains of α-Al changed from large grains to roughly spherical and then to small rounded grains with increasing Ti content, the micro-hardness of the alloy increases with increasing Ti, and XRD results confirm the formation of TiAl3 intermetallic compound during sintering.

X-ray diffraction analysis of three-dimensional residual stress fields reveals origins of thermal fatigue in uncoated and coated steel

2010 ◽  
Vol 62 (10) ◽  
pp. 774-777 ◽  
Author(s):  
C. Kirchlechner ◽  
K.J. Martinschitz ◽  
R. Daniel ◽  
C. Mitterer ◽  
J. Donges ◽  
...  
Keyword(s):  
Residual Stress ◽  
Diffraction Analysis ◽  
Thermal Fatigue ◽  
Three Dimensional ◽  
Stress Fields ◽  
Coated Steel ◽  
X Ray Diffraction ◽  
X Ray

Preparation of Ceramic Moulds with Zirconia Coatings for the Investment Casting of TiAl Alloys

2010 ◽  
Vol 146-147 ◽  
pp. 499-505
Author(s):  
Yuong Chen ◽  
Yan Fei Chen ◽  
Shu Long Xiao ◽  
Jing Tian ◽  
Li Juan Xu
Keyword(s):  
Investment Casting ◽  
Preparation Method ◽  
Processing Parameters ◽  
Optical Microscope ◽  
Interfacial Reactions ◽  
Zirconia Coating ◽  
X Ray Diffraction ◽  
Tial Alloys ◽  
X Ray ◽  
Scanning Electron

In this paper, a preparation method concerning ceramic moulds with zirconia coating used for the investment casting of TiAl alloys has been described. The processing technology of ceramic moulds was verified successfully using the ceramic moulds with zirconia coating prepared by recommended processing parameters. Interfacial reactions between ceramic moulds and TiAl alloys examined by OM (optical microscope), SEM (scanning electron microscopy) and XRD (X-ray diffraction) are presented in this paper. The results reveal that the thickness of interfacial reactions layer was about 20 μm.

Effect of Mo on As-Cast Microstructure of a Modified 718 Alloy

2014 ◽  
Vol 788 ◽  
pp. 483-487 ◽  
Author(s):  
Feng Qi ◽  
Wen Ru Sun ◽  
Xin Xin ◽  
Dan Jia ◽  
Zhuang Qi Hu
Keyword(s):  
Electron Microscope ◽  
Optical Microscope ◽  
Laves Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Present Test ◽  
Δ Phase ◽  
New Phase ◽  
Scanning Electron ◽  
Cast Microstructure

The microstructure of as-cast 718 alloy after modified with Mo has been investigated by means of optical microscope (OM), scanning electron microscope (SEM) and X-ray diffraction (XRD). It was found that the dendrite arm space was widened and the interdendritic area was reduced by increasing Mo addition. And no new phase was precipitated in the modified alloys by Mo addition in the range of the present test. The addition of Mo promoted the precipitated of Laves phase, restrained the formation of δ phase, and elevated melting point of the Laves phase.

scholarly journals Surface Morphology Study of Chemical Vapor Transport of ZnO Crystals

Scanning ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Long Fan ◽  
Jia Li ◽  
Dawei Yan ◽  
Liping Peng ◽  
Tao Jiang ◽  
...  
Keyword(s):  
Grown Crystal ◽  
Chemical Vapor ◽  
Optical Microscope ◽  
Vapor Transport ◽  
Chemical Vapor Transport ◽  
X Ray Diffraction ◽  
Vapor Interface ◽  
X Ray ◽  
Thermal Etching ◽  
Scanning Electron

A chemical vapor transport (CVT) method was implemented to grow bulk ZnO crystals. X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), and optical microscope (OM) studies were carried out to characterize the surface properties of the grown crystal. The XRD result indicated the exposed solid-vapor interface of the as-grown crystal was composed of (0001) and {101-1} faces. Using SEM and OM, we observed small hexagonal pyramids and microstructures formed of crosslines on the as-grown crystal and found hexagonal thermal etching pits on the surfaces of seed crystals. The formation, evolution, and distribution mechanisms of the microstructures were investigated.

Sign in / Sign up

Export Citation Format

Share Document