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.

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.

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.

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.

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.

Effect of Sr Addition on the Microstructure of Mg-6Zn-2Al-2Ca Alloy

2011 ◽  
Vol 391-392 ◽  
pp. 993-997
Author(s):  
Jun Hua You ◽  
Wei Gang Zhang ◽  
Ke Qiang Qiu
Keyword(s):  
Electron Microscope ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
Continuous Precipitation ◽  
X Ray ◽  
Β Phase ◽  
Refined Microstructure ◽  
Result Show ◽  
Alloy Microstructure ◽  
Scanning Electron

The effect of Sr addition on microstructure evolution of Mg-6Zn-2Al-2Ca-xSr (x=0.5, 1, 2, 3）alloys were investigated by using scanning electron microscope (SEM), X-ray diffraction (XRD) and optical microscope. The result show that Sr constitutional under cooling can significantly refined microstructure of alloys and formed rod-shaped Al4Sr phase in Mg-6Zn-2Al-2Ca alloys, while alloy microstructure turned to be coarse with further increase in Sr content. The addition of Sr slows down the precipitation power of Mg-6Zn-2Al-2Ca alloys and inhabits the β phase continuous precipitation.

Preparation of Bulk Polycrystalline MnGexSby (x = 0.5-1.0; y = 1.5-2.2) Doped with Co or Fe

2015 ◽  
Vol 760 ◽  
pp. 329-334
Author(s):  
Madalin Ion Rusu ◽  
Daniel Tenciu ◽  
Nicolae Catalin Zoita ◽  
Roger Notonier ◽  
Alain Tonetto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Preparation Method ◽  
Diluted Magnetic Semiconductor ◽  
Bulk Material ◽  
Magnetic Semiconductor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diluted Magnetic ◽  
Scanning Electron

Bulk polycrystalline MnGexSby materials doped with Co or Fe were prepared and investigated with the aim of obtaining new diluted magnetic semiconductor (DMS) materials. An innovative preparation method was also established. Investigation techniques like X-ray diffraction (XRD), Raman scattering, and scanning electron microscopy (SEM) associated with energy dispersive X-ray analysis (EDX) have been employed to derive the structural properties and the composition of the bulk material.

EFFECT OF Cr3C2 ADDITION ON THE MICROSTRUCTURE AND PROPERTIES OF LASER CLADDING NiCrBSi COATINGS

2019 ◽  
Vol 26 (06) ◽  
pp. 1850207 ◽  
Author(s):  
XUELONG PING ◽  
SHUTING SUN ◽  
FENG WANG ◽  
HANGUANG FU ◽  
JIAN LIN ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Laser Cladding ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nicrbsi Coatings ◽  
Scanning Electron ◽  
Microhardness Tester

In this paper, the enhancement of NiCrBSi coatings by adding Cr3C2 were investigated. The NiCrBSi coatings with different additions of Cr3C2 were produced by laser cladding. The microstructure, hardness and wear resistance of the coatings were studied by optical microscope (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), microhardness tester and M-200 wear tester. It is found that the main phases in the coatings are [Formula: see text]-Ni, Cr[Formula: see text]C6 and Cr7C3, and they also contain a small amount of CrB, Ni4B3 and Ni3Si2. Moreover, with the increase of Cr3C2 addition, the microhardness and wear resistance of coatings are obviously improved. When the addition of Cr3C2 is 20%, the wear resistance of the coating is the best, and the wear resistance of the coating increased by 191.2% than that of the Cr3C2-free coating. The wear resistance of coating decreases when the addition of Cr3C2 reaches 30%.

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.

Sign in / Sign up

Export Citation Format

Share Document