Laser Repair Cladding of K418 Ni-Base Superalloy by CoCrNiW Powder

2011 ◽  
Vol 291-294 ◽  
pp. 1417-1420
Author(s):  
Chang Jun Chen ◽  
Qin Cao ◽  
Min Zhang ◽  
Qing Ming Chang ◽  
Shi Chang Zhang
Keyword(s):  
Electron Microscope ◽  
Optimum Condition ◽  
Heat Input ◽  
Optical Microscope ◽  
X Ray ◽  
Cladding Layer ◽  
Metallurgical Bonding ◽  
Base Superalloy ◽  
Scanning Electron ◽  
Characteristic Microstructure

Laser cladding has been taken into consideration for repairing K418 Ni-based superalloy material with CoCrNiW powder.Composition of cladding materials was revealed by energy dispersive X-ray spectrum(EDS). The characteristic microstructure of the cladding layer and interface were investigated by using an optical microscope and scanning electron microscope(SEM).Cladding coatings were obtained for different process parameters, and a detailed study of the effects of these parameters has been carried out by SEM. Metallurgical bonding between the cladding layer and substrate materials was obtained.Effect of heat input on cladding cracking susceptibility has been studied to obtain optimum condition for crack-free welds. Variations in cracking susceptibility as a function of heat input is discussed with reference to metallurgical characteristics of the clads. The corresponding microstructure induced by different heat input was discussed in this paper too.

Characteristics of Ni–Cr–Fe laser clad layers on EA4T steel

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744031
Author(s):  
Wenjing Chen ◽  
Hui Chen ◽  
Yongjing Wang ◽  
Congchen Li ◽  
Xiaoli Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cladding Layer ◽  
Metallurgical Bonding ◽  
The Matrix ◽  
Feeding Speed ◽  
Upper Bainite ◽  
Scanning Electron

The Ni–Cr–Fe metal powder was deposited on EA4T steel by laser cladding technology. The microstructure and chemical composition of the cladding layer were analyzed by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The bonding ability between the cladding layer and the matrix was measured. The results showed that the bonding between the cladding layer and the EA4T steel was metallurgical bonding. The microstructure of cladding layer was composed of planar crystals, columnar crystals and dendrite, which consisted of Cr2Ni3, [Formula: see text] phase, M[Formula: see text]C6 and Ni3B phases. When the powder feeding speed reached 4 g/min, the upper bainite occurred in the heat affected zone (HAZ). Moreover, the tensile strength of the joint increased, while the yield strength and the ductility decreased.

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.

Electron Microscopy and X-Ray Microanalysis in Forensic Science

1973 ◽  
Vol 56 (4) ◽  
pp. 930-943
Author(s):  
John L Brown ◽  
James W Johnson
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Chemical Elements ◽  
Optical Microscope ◽  
Forensic Analysis ◽  
Depth Of Focus ◽  
Crystalline Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Abstract The optical microscope has long been an important tool in forensic analysis for the comparison of firearms markings and the examination and identification of other minute bits of evidence. The electron microscope permits the examination of even smaller details and offers analytical capabilities unique to the type of instrument used. The transmission electron microscope can be used to identify very small amounts of crystalline materials through the process of electron diffraction. The scanning electron microscope can frequently supersede the optical microscope because of its superior depth of focus and range of magnification. When it is equipped with an energy dispersive X-ray analyzer, most of the chemical elements in a sample can be determined. Applications of these instruments have provided some interesting and instructive results in forensic analysis.

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.

The Elaboration of an Iron Aluminium Alloy and the Study of Impact of the Addition Element on its Physical and Mechanical Properties

2013 ◽  
Vol 686 ◽  
pp. 211-215
Author(s):  
Nadia Metidji ◽  
Nacer Eddine Bacha ◽  
Djamal Saidi ◽  
Slimane Boutarfaia
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Morphological Changes ◽  
Physical And Mechanical Properties ◽  
Antiphase Domain ◽  
Optical Microscope ◽  
Micro Hardness ◽  
X Ray ◽  
B Additions ◽  
Scanning Electron

This work has been undertaken in order to determine the effect of alloying with Ni, Mo and B additions on physical and mechanical properties of FeAl alloys. The structural evolutions and morphological changes alloys were characterized by X. ray diffractometry (XRD), Scanning Electron Microscope (SEM) and an Optical Microscope. Antiphase domain sizes and morphologies are reported and correlations between such ordening phenomena, phase precipitations and mechanical properties (micro hardness at low temperature) are discussed.

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.

The Oxide Inclusion and Heat-Affected-Zone Toughness for Low Carbon Bridge Steels

2012 ◽  
Vol 562-564 ◽  
pp. 31-34
Author(s):  
Shu Rui Li ◽  
Xue Min Wang ◽  
Chao Chao Zheng ◽  
Xin Lai He
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Scanning Electron Microscope ◽  
Impact Energy ◽  
Heat Input ◽  
Oxide Inclusion ◽  
Optical Microscope ◽  
Low Carbon ◽  
Temperature Impact ◽  
Scanning Electron

By welding thermo-simulation and actual welding practices, the microstructure and properties of low carbon bridge steels has been studied with the aid of optical microscope, scanning electron microscope. The experimental results show that by the oxide introducing melting technology there are many complex inclusions composed of oxide containing Ti and MnS. These inclusions are spherical and they are distributed homogeneously. During the welding thermo-simulation these oxide inclusions will promote the nucleation of acicular ferrite and make the microstructure in HAZ finer. Therefore the toughness in HAZ is good whether in welding thermo-simulation even if the heat input reaches to 200kJ/cm. In actual welding the heat input is 88kJ/cm and the low temperature impact energy still can reach 110J.

Mineralogical Composition and Microstructure of Sinter in Ansteel

2014 ◽  
Vol 685 ◽  
pp. 37-42
Author(s):  
Jie Liu ◽  
Ming Shun Zhou ◽  
Li Wei Zhai ◽  
Hui Zhang ◽  
Li Bing Xu
Keyword(s):  
Electron Microscope ◽  
Glass Phase ◽  
Mineralogical Composition ◽  
Optical Microscope ◽  
Dicalcium Silicate ◽  
Calcium Ferrite ◽  
X Ray Diffraction ◽  
Metallurgical Property ◽  
X Ray ◽  
Scanning Electron

In order to improve the qualities of sinter of Ansteel, the sinter’s metallurgical property was examined and analyzed that from the second workshop and the fourth workshop of ironmaking plant. And mineralogical composition and microstructure in high basicities sinter were investigated and analyzed by the X-ray diffraction, the optical microscope and the scanning electron microscope in laboratory. It was found that the differences between in sinter’s mineralogical composition and microstructures are according with the differences in chemical composition and the metallurgical indexes. Both the sinter’s minerals are mainly composed of hematite, magnetite or maghemite, calcium ferrite, dicalcium silicate, silicate glass phase. The content of the carbon in the fourth workshop is higher. So, it should decrease the content of the carbon that makes the microstructure of the sinter more rational.

Characterisation of Phases and Lattice Parameter in Eutectic and Hypoeutectic Al-Si-Mg-Ce Cast Alloy

2012 ◽  
Vol 620 ◽  
pp. 50-54
Author(s):  
A.S. Anasyida ◽  
Zuhailawati Hussain ◽  
Abdul Razak Daud ◽  
M.J. Ghazali
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Cast Alloy ◽  
Optical Microscope ◽  
Lattice Parameter ◽  
X Ray ◽  
Casting Technique ◽  
Conventional Casting ◽  
Ce Content ◽  
Scanning Electron

The purpose of this work is to understand the phases formation and lattice parameter changes with addition 0.6 to 2.7 wt.% in Al-Si-Mg-Ce cast alloy. Al-Si-Mg-Ce eutectic and hypoeutectic cast alloy were prepared by conventional casting technique. The alloys were investigated by using optical microscope, Scanning electron microscope (SEM) and X-Ray diffractometry (XRD). The addition of Ce resulted in precipitation of Al4Ce in eutectic cast alloy and CeMg2Si2 in hypoeutectic cast alloy. The lattice parameter of Al increases with increase in Ce content wheareas lattice parameter of Si phase decreases as the Ce content increases.

Microstructure and Mechanical Properties of Ti-Al-Mo-V-Ta Alloys

2013 ◽  
Vol 785-786 ◽  
pp. 86-90
Author(s):  
D.H. Xiao ◽  
X.X. Li ◽  
X.Z. Wu ◽  
Dan Liu ◽  
Y.S. Zhang
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Relative Density ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alpha Beta ◽  
Hot Pressing Sintering ◽  
Scanning Electron

P/M Ti-Al-Mo-V-Ta alpha-beta alloys were processed by hot-pressing sintering technique. The effects of Ta additions on microstructure and properties of the Ti-5Al-4Mo-4V alloys were investigated using X-ray diffraction, optical microscope, scanning electron microscope and mechanical properties tests. The results show that minor Ta addition improves the relative density and the mechanical properties of P/M Ti-5Al-4Mo-4V alloys. After sintering for 4h at 1623 K, the relative density and compression strength of Ti-5Al-4Mo-4V-5Ta alloy are 99.3% and 1950 MPa.

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