The Research on the Microstructure and Property of Gear with Sinter Powder Material

2010 ◽  
Vol 37-38 ◽  
pp. 1558-1560 ◽  
Author(s):  
Bai Yang Lou ◽  
Fang Liang Dong ◽  
Bin Xu
Keyword(s):  
Powder Material ◽  
Base Material ◽  
Residual Austenite ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Tempered Martensite ◽  
Common Part ◽  
Energy Spectrometer ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

Gear is a widely used common part of machinery, which is of good lubricate property and low materials consumption when it is made of sinter powder material. In this paper, the chemical composition, microstructure and property of sintered gear were investigated with optical microscope, scan electronic microscope, micro hardness meter and X-diffraction energy spectrometer. The results show that the microstructure of the gear includes of tempered martensite, carbide, residual austenite and a small quantity of cavity. The distribution of iron element is even. The copper and nickel distribute unevenly and cover around the surface of carbide in gear material which makes different property of covered layer itself between carbide and base material. The existing of covered layer and weak grain-boundary strength are main reason for gear brittle fracture. The gear’s toughness can be increased by optimizing sintering technology and heat treatment.

Failure Analysis and Strengthening Method for Circular Diamond Saw Blade

2010 ◽  
Vol 152-153 ◽  
pp. 1616-1619
Author(s):  
Bai Yang Lou ◽  
Pei Hua Li ◽  
Le Guo Li
Keyword(s):  
Wear Resistance ◽  
Optical Microscope ◽  
Wear Coefficient ◽  
Diamond Saw ◽  
Enhance Wear Resistance ◽  
Saw Blade ◽  
Scan Electronic Microscope ◽  
Energy Disperse Spectroscopy ◽  
Electronic Microscope ◽  
Strengthening Method

The main causes of segment failure of diamond saw blade are studied in this paper. The segment material, the microstructure and the wear resistance of saw blade material were studied with scan electronic microscope, energy disperse spectroscopy, hardness meter, optical microscope. The results shows that the addition of alloying elements could refine grains, improve the holding force of matrix to diamond, enhance wear resistance of matrix to diamond, and decrease wear coefficient about 20%.

Microstructure and Mechanical Properties of (CrTiNb)N Films

2014 ◽  
Vol 915-916 ◽  
pp. 808-811
Author(s):  
Yu Feng ◽  
Jun Zhang
Keyword(s):  
Mechanical Properties ◽  
Bias Voltage ◽  
High Speed ◽  
High Speed Steel ◽  
Fracture Morphology ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Friction Resistance ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

(CrTiNb)N hard reactive films are prepared by multi-arc ion plating technology using the combination of Ti-Nb alloy target and Cr target. The high speed steel (HSS) is adopted as substrate. The surface and cross-fracture morphology, the surface compositions and the phase structures of the as-deposited (CrTiNb)N films are observed and measured by scan electronic microscope (SEM) and X-ray diffraction (XRD). The mechanical properties including the micro-hardness, the adhesion between film and substrate, the friction and wear resistance of the as-deposited (CrTiNb)N films are systemically investigated. The effects of deposition bias voltage and the addition of Nb element on the as-deposited (CrTiNb)N films are discussed. It is revealed that the optimally comprehensive performances including the micro-hardness, the adhesion and also the friction resistance can be achieved by the (CrTiNb)N hard reactive films with bias voltage of 200V.

Procedure and Discussion of Failure Analysis in Iron-Steel Materials

2014 ◽  
Vol 556-562 ◽  
pp. 261-264
Author(s):  
Zhi Gang Wang ◽  
Lu Dan Shi ◽  
Min Jing ◽  
Yong Xu
Keyword(s):  
Failure Analysis ◽  
Hot Forging ◽  
High Hardness ◽  
Optical Microscope ◽  
Metallographic Analysis ◽  
Good Teaching ◽  
H13 Steel ◽  
Quenching Temperature ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

The failure analysis of the H13 steel hot-forging mould is the main content in the open experiment. The scan electronic microscope and the optical microscope are used to analyze the failure workpiece in this experiment. The over-high quenching temperature, the too low drawing temperature, the insufficient drawing time and frequency, the over-high hardness value are the main reasons of fracture failure of the mould. The work environment of the failure materials, the heat treatment processing, the metallographic analysis, the fracture analysis and the using of test standard are the important aspects which the students should know. The students can learn how to analyze problem and how to solve them from the open experiments which is a good teaching try.

Evolutions of Microstructure for Multilayered Al-Mg Alloy Composites by Accumulation Roll Bonding (ARB) Process

2011 ◽  
Vol 411 ◽  
pp. 527-531
Author(s):  
Bing Zhang ◽  
Zhong Wei Chen ◽  
Shou Qian Yuan ◽  
Tian Li Zhao
Keyword(s):  
Multilayer Structure ◽  
Optical Microscope ◽  
Alloy Layer ◽  
Mg Alloy ◽  
Micro Hardness ◽  
Roll Bonding ◽  
Fine Grained ◽  
Hardness Tester ◽  
Average Grain Size ◽  
Evolution Of Microstructure

In this paper, accumulative roll bonding (ARB) has been used to prepare the Al/Mg alloy multilayer structure composite materials with 1060Al sheet and MB2 sheet. The evolution of microstructure of the cladding materials during ARB processes was observed by optical microscope, scanning electron microscopy, and micro-hardness was measured by micro-hardness tester. The results show that a multilayer structure material of Al/Mg alloy with excellent bonding characteristics and fine grained microstructure was prepared by ARB processes. With the ARB cycles increasing, Mg alloy layer in multilayer composite material was necked and fractured, and the hardness of the Al and Mg alloy was increased. Average grain size was less than 1μm after ARB4 cycles.

scholarly journals PELAPISAN PERMUKAAN DALAM NOSEL ROKET RKX100 DENGAN Cr2C3-NiCr HVOF: OPTIMASI KEKUATAN LEKAT MELALUI VARIASI KEKASARAN PERMUKAAN

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Bondan T.Sofyan ◽  
Yus Prasetyo ◽  
Sayid Ardiansyah ◽  
Yus Prasetyo ◽  
Edy Sofyan
Keyword(s):  
Surface Roughness ◽  
Thermal Spray ◽  
Bonding Strength ◽  
Spray Coating ◽  
Hardness Measurement ◽  
Thermal Spray Coating ◽  
Optical Microscope ◽  
Mechanical Interlocking ◽  
Micro Hardness ◽  
Scanning Electron

Nozzle of RKX100 rocket contributes 30 percent to the total weight of the structure, so that allowing further research on weight reduction. An alternative for this is by substitution of massive graphite, which is currently used as thermal protector in the nozzle, with thin layer of HVOF (High Velocity Oxy-Fuel) thermal spray layer. A series of study on the characteristics of various type of HVOF coating material have been being conducted. This paper presented the investigation on the HVOF Cr2C3-NiCr thermal spray coating, in particular, the optimization of bonding strength by varying surface roughness of substrates. Characterization included bonding strength test, micro hardness measurement and micro structural observation with optical microscope and scanning electron micriscope (SEM). The results showed that grit blasting pressure increass the surface roughness from 4,54 um to 5.72 um at the pressure of 6 bar. Average micro hardness of the coating was 631 VHN 300. Coating applied to the surface with rougness of 5.42 um possessed the highest bonding strength, 44 MPa. Microstructural observation by using optical microscope and scanning electron microscope (SEM) confirmed dense lamellae structure with variable composition. High coating adherence was found to be due to mechanical interlocking.

scholarly journals Influence of the resistive-pulse welding parameters of nickel super-alloys on selected properties of the connection

Mechanik ◽  
2017 ◽  
Vol 90 (11) ◽  
pp. 1060-1062
Author(s):  
Sławomir Spadło ◽  
Wojciech Depczyński ◽  
Piotr Młynarczyk ◽  
Tadeusz Gajewski ◽  
Jarosław Dąbrowa
Keyword(s):  
Optical Microscope ◽  
Mechanical Tests ◽  
Welding Parameters ◽  
Thin Sheets ◽  
Micro Hardness ◽  
Hastelloy X ◽  
Haynes 230 ◽  
Hardness Tester ◽  
Resistive Pulse ◽  
Pulse Welding

Microstructure and mechanical tests of welds of thin sheets made from nickel-based super-alloys (Haynes 230 and Hastelloy X) were presented. The welds were made using the resistive-pulse micro-welding method using the WS 7000S device. The micro-hardness of the joints was measured with a Matsuzawa Vickers MX 100 hardness tester at 100 G (0.98 N). Metallographic observations of the prepared micro-sections were performed using the Nikon Eclipse MA200 optical microscope at various magnifications. The metallographic microstructure studies were supplemented by linear analysis of the chemical composition, for which the OXFORD X-MAX electron microscope was applied.

Microstructural Characterization and Tensile Behavior of TA1 Titanium Alloy Sheet Welded by Electron Beam Welding

2021 ◽  
Vol 1027 ◽  
pp. 149-154
Author(s):  
Sen Dong Gu ◽  
Ji Peng Zhao ◽  
Rui Jie Ouyang ◽  
Yong Hong Zhang
Keyword(s):  
Titanium Alloy ◽  
Electron Beam ◽  
Fusion Zone ◽  
Heat Affected Zone ◽  
Electron Beam Welding ◽  
Base Material ◽  
Optical Microscope ◽  
Alloy Sheet ◽  
Tensile Behavior ◽  
Electron Backscattered Diffraction

In the present study, TA1 titanium alloy sheets with a thickness of 0.8mm were welded by electron beam welding. Microstructure of the welded region was investigated using optical microscope and electron backscattered diffraction. Then, the tensile test was conducted to analyse the tensile behavior of the welded sheets as well as the fractography of the fracture surfaces. It is shown that the mean grain size in the heat-affected zone is smaller than that in the fusion zone and base material. The strength of the base metal is lower than that of the fusion zone and heat-affected zone. The average values of the yield strength, tensile strength and elongation of the tensile specimens are 224MPa, 335MPa and 35%, respectively. In addition, the tensile specimens of the welded sheets suffer both ductile and brittle deformation during the tensile tests.

Effect of Friction Stir Processing Parameters on the Properties of AA7075-T73/Al2O3 Surface Metal Matrix Composite

2020 ◽  
Vol 1002 ◽  
pp. 140-150
Author(s):  
Ali H. Al-Helli ◽  
Ahmed R. Alhamaoy ◽  
Ayad Murad Takhakh
Keyword(s):  
Friction Stir Processing ◽  
Particle Distribution ◽  
Surface Hardness ◽  
Base Material ◽  
Processing Parameters ◽  
Optical Microscope ◽  
Friction Stir ◽  
Surface Composite ◽  
Surface Metal ◽  
Number Of Passes

Friction Stir Processing (FSP) technology was wielded to output the Al7075/ Al2O3 surface composite. The effects parameters of processing method on particle distribution have been studied. The microstructure and mechanical characteristics of the samples were examined using the optical microscope, SEM and hardness examination. Acquired consequences, showed that Al2O3 particles were in a good interior distribution inside the basement. This technique produced excellent bonding between the surface composite and the base material. On other hand the surface hardness was increased about 25% as compared with the substrate. In addition, grain matrix refinement and enhanced particle distribution were obtained after each FSP pass. Also the dispersion of Al2O3 particles in the stirred area became more homogeneous and the average hardness improved by increasing the number of passes.

Surface Properties of TiN Films on AZ 31 Magnesium Alloys Deposited by Magnetron Sputtering Technique

2011 ◽  
Vol 314-316 ◽  
pp. 53-57 ◽  
Author(s):  
Xiang Rong Zhu ◽  
Nai Ci Bing ◽  
Zhong Ling Wei ◽  
Qiu Rong Chen
Keyword(s):  
Magnetron Sputtering ◽  
Surface Properties ◽  
Structural Defects ◽  
Micro Hardness ◽  
Dense Structure ◽  
Tin Films ◽  
Tin Film ◽  
Indentation Experiment ◽  
The Stability ◽  
Electronic Microscope

TiN films were deposited on the AZ 31 magnesium alloy substrates by d.c. magnetron sputtering technique. The surface properties of the films were investigated. The scanning electronic microscope observations reveal the dense structure characteristics of as-deposited TiN films. Under 200°C heat treatment for 30 minutes or 4 times’ heat cycles at 85°C for one hour, no structural defects such as cracks are observed on the surface of the films. Adhesion experiment further demonstrates the stability of the film and the strong combination between the film and the substrate. Nano-indentation experiment shows that the average micro-hardness of TiN film reaches 23.85 Gpa. Finally, the corrosion experiments in simulated body fluid initially reveal the degradation property of TiN film.

scholarly journals Evaluation of Cryogenic Mechanical Properties of Resistance Seam-Welded Invar Alloy Sheet by Instrumented Indentation Test

2020 ◽  
Vol 8 (12) ◽  
pp. 1009
Author(s):  
Seunghun Choi ◽  
Jongho Won ◽  
Jung-Jun Lee ◽  
Hee-Keun Lee ◽  
Seong-Min Kim ◽  
...  
Keyword(s):  
Grain Size ◽  
Plastic Zone ◽  
Base Material ◽  
Indentation Test ◽  
Welding Current ◽  
Optical Microscope ◽  
Alloy Sheet ◽  
Invar Alloy ◽  
Instrumented Indentation ◽  
Average Grain Size

Invar alloy sheet was welded by resistance seam welding (RSW) with a constant electrode force and three different welding currents. Tensile properties were evaluated using instrumented indentation testing (IIT) with a spherical indenter and microstructure observations were obtained under an optical microscope. IIT performed on the base material at room temperature (RT) and −163 °C, a cryogenic temperature (CT), gave results in good agreement with those of tensile testing. The strength of each zone was higher in the order of heat-affected zone (HAZ) < weld nugget (WN) < base material (BM) because the amount of cold working was least in the BM, heavy metal elements and carbon vaporized during melting, and the WN was formed more tightly than the HAZ, effectively constraining the plastic zone generated by the indentation. As for the welding current, the nugget, which becomes larger and tighter as the current increases, more effectively constrained the plastic zone in the indentation, and this soon increased the strength. Generally, Invar is known to consist of single-phase austenite, and microstructure observations have confirmed that the average grain size is ordered as BM < HAZ < WN. Fan-like columnar grains developed in the direction of the temperature gradient, and equiaxed grains were observed near the BM. It was confirmed that the grain size in the WN also increases as the current is increased. Interestingly, the constraint effect with increasing nugget size was more important for strength than the grain size.

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