Influence of Ti on the Microstructure and Performance of Fe-Cr Alloy Cladding Layer

2016 ◽  
Vol 849 ◽  
pp. 709-715
Author(s):  
Jian Yang Liu ◽  
Qing Tao ◽  
Wei Lai ◽  
Wei Wei Tang ◽  
Jian Wang ◽  
...  
Keyword(s):  
Mass Fraction ◽  
Hardness Test ◽  
Wear Volume ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Hardness Tester ◽  
Optical Micrograph ◽  
Series Alloy ◽  
And Performance ◽  
Microstructure And Performance

Considering the multi-porous and rimous Fe-Cr series alloy coatings deposited on Q235 steel by plasma arc welding, the mass fraction of 0%, 2%, 4%, 6%, 8% Ti is mixed into Fe-Cr alloy powder. The microstructure and characteristics of the Fe-Cr series alloys with a range content of Ti were investigated using optical micrograph (OM), X-ray diffraction (XRD), scanning electron micrograph (SEM) Digital Micro-hardness Tester and M-2000 dry abrasion tester. The major phase of the Fe-Cr layers is dendrite with the lath carbide mixed between the limb of dendrite and the grains refine with addition of Ti. The XRD result indicates the main phases are (Fe-Cr) solution, Cr23C6, and TiC, while the result of Digital Micro-hardness test shows the microhardness increases with the mass fraction of Ti till it comes to 4% and decreases with the following addition of Ti. The highest average hardness of layer is 750HV with content of 4% Ti, while the coating with 2% Ti appears better wear resistance with the least wear volume for the match of toughness matrix and hard phase. Hence, the coating with 2% to 4% Ti shows the best property.

Micro-Hardness and Morphology of LDPE Influenced by Beta Radiation

2014 ◽  
Vol 606 ◽  
pp. 253-256 ◽  
Author(s):  
Martin Ovsik ◽  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hardness Test ◽  
Polymer Materials ◽  
Beta Radiation ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Depth Sensing ◽  
Surface Layers ◽  
Hardness Values ◽  
Different Doses

This article deals with the influence of different doses of Beta radiation to the structure and mico-mechanical properties of Low-density polyethylene (LDPE). Hard surface layers of polymer materials, especially LDPE, can be formed by radiation cross-linking by β radiation with doses of 33, 66 and 99 kGy. Material properties created by β radiation are measured by micro-hardness test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 66 and 99 kGy, when the micro-hardness values increased by about 21%. The changes were examined and confirmed by X-ray diffraction.

The Structure and Electrical Property of sp2 Rich Carbon Films by Magnetron Sputtering

2014 ◽  
Vol 998-999 ◽  
pp. 120-123
Author(s):  
Jun Du ◽  
Xiao Ying Zhu ◽  
Yan Zang ◽  
Lei Guo
Keyword(s):  
Electrical Resistivity ◽  
Magnetron Sputtering ◽  
Carbon Films ◽  
Wear Volume ◽  
Chemical Bonds ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Sputtering Deposition ◽  
X Ray ◽  
Pin On Disk

sp2 rich carbon films were produced by using magnetron sputtering deposition. The hardness, friction coefficient and wear volume were elevated by Knoop micro-hardness and pin-on-disk tester; The composition and microstructure of the carbon films have been characterized in detail by combining the techniques of Rutherford Backscattering Spectrum (RBS), X-Ray Photoelectron Spectrum (XPS) and X-Ray Diffraction (XRD); the electrical resistivity was measured by Four Probe Methods (FPM). It is found that: the films hardness are 11~17GPa (HK0.05), the friction coefficients are 0.1-0.2, the wear rate is 10-15m3/Nm; The maximum intensity position in the C1s indicates the chemical bonds are mainly sp2; the electrical resistivity is 1~2×10-4Ω·m. XRD proves these carbon films are amorphous.

Characterisation of WC-17Co and WC-9Ni HVOF Sprayed Cermet Coatings

2016 ◽  
Vol 840 ◽  
pp. 331-335
Author(s):  
Nur Amira Mohd Rabani ◽  
Zakiah Kamdi
Keyword(s):  
Steel Substrate ◽  
Optical Microscope ◽  
Binder Phase ◽  
High Porosity ◽  
Tungsten Carbides ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tester ◽  
Vickers Micro Hardness

Cemented tungsten carbides have been paid much attention due its better mechanical properties with excellent combination of hardness and toughness characteristics. The hard WC particles in the coating provide hardness and wear resistance, while the ductile binder such as Co and Ni contribute to toughness and strength. WC-17wt.% Co and WC-9wt.% Ni powders have been sprayed by the HVOF method to form coatings approximately 300μm and 150μm thick onto AISI 1018 steel substrate. Both coatings have been prepared and supplied by an external vendor. The coatings were examined using optical microscope (OM), scanning electron microscope (SEM), and X-Ray diffraction (XRD). The hardness of both coatings were also measured using Vickers micro-hardness tester. The microstructure of the coatings has been analyzed and found to consist of WC, brittle W2C phase, metallic W phase, and amorphous binder phase of Co and Ni. It is found that WC-Ni has a higher hardness value compared to WC-Co due to high porosity distribution.

scholarly journals Mechanical Properties of Anatomic Finishing Files: XP-Endo Finisher and XP-Clean

2018 ◽  
Vol 29 (2) ◽  
pp. 208-213 ◽  
Author(s):  
Eduarda Santiago Vaz-Garcia ◽  
Victor Talarico Leal Vieira ◽  
Natasha Pereira da Silva Ferreira Petitet ◽  
Edson Jorge Lima Moreira ◽  
Hélio Pereira Lopes ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Visual Inspection ◽  
Hardness Test ◽  
Cyclic Fatigue ◽  
Radius Of Curvature ◽  
Weibull Analysis ◽  
Micro Hardness ◽  
Significance Level ◽  
Hardness Tester ◽  
Improved Performance

Abstract The aim of the present study was to evaluate the cyclic fatigue of two anatomic finishing files: XP-Endo Finisher and XP-Clean. Roughness pattern and the micro-hardness of the files were also assessed. Instruments were subjected to cyclic fatigue resistance measuring the time to fracture in an artificial stainless-steel canal with a 60° angle and a 5-mm radius of curvature. The fracture surface of all fragments was examined with a scanning electron microscope. The roughness of the working parts was quantified by using a profilometer and the micro-hardness test was carried out using a Vickers hardness tester. Results were statistically analyzed using a student´s t-test at a significance level of P < 0.05. Weibull analysis was also performed. XP-Endo Finisher presented significantly longer cyclic fatigue life than XP-Clean instruments (P<0.05). XP-Endo Finisher was able to withstand 1000% more cycles to fracture when compared to XP-Clean instruments. SEM visual inspection of the fracture surfaces revealed fractographic characteristics of ductile fracture in all tested instruments; wide-ranging forms of dimples were identified and no plastic deformation in the helical shaft of the fractured instruments was observed. When mean life was compared XP-Endo Finisher lasted longer than XP-Clean with a probability of 99.9%. XP-Endo Finisher instruments also exhibited significantly lower roughness than XP-Clean instruments (P<0.05). No differences in the micro-hardness was observed between the files (P>0.05). It can be concluded that XP-Endo Finisher instruments showed improved performance when compared with XP-Clean instruments, demonstrating higher cyclic fatigue resistance and lower roughness.

scholarly journals Perbedaan Penggunaan Bahan Desensitizing dan Tanpa Desensitizing Pasca Bleaching Ekstra-Koronal terhadap Kekerasan Email

2012 ◽  
Vol 19 (2) ◽  
pp. 119
Author(s):  
Wignyo Hadriyanto
Keyword(s):  
Vickers Hardness ◽  
Artificial Saliva ◽  
Hardness Test ◽  
Acrylic Resin ◽  
Micro Hardness ◽  
Vickers Hardness Number ◽  
Hardness Tester ◽  
Group I ◽  
Significant Difference ◽  
The Subject

Latar Belakang. Pada bleaching ekstrakoronal diketahui terjadi proses demineralisasi sehingga terjadi hiersensitivitas dentin. UltraEZ salah satu bahan desensitizing yang dapat mengurangi hipersensitivitas akibat demineralisasi email pasca bleaching ekstrakoronal terkini. Tujuan penelitian ini bertujuan untuk mengetahui perbedaan kekerasan email pasca pemutihan gigi ekstra-koronal dengan aplikasi bahan desensitizing dan tanpa aplikasi bahan desensitizing. Metode penelitian ini menggunakan 20 gigi premolar permanen pasca pencabutanyang masih utuh dan direndam dalam saliva buatan, kemudian dilakukan pemolesan pada bagian bukal dengan menggunakan pasta profilaksis kemudian gigi dicuci dan dikeringkan. Bahan pemutih Opalescence Xtra Boost diaplikasikan pada semua permukaan bukal gigi premolar kemudian dibagi menjadi 2 kelompok yaitu kelompok I, II, masing-masing kelompok sebanyak 10 gigi. Kelompok I sebagai kelompok control setelah dilakukan pemutihan, tidak dilakukan aplikasi Ultra-EZ, dimasukkan dalam wadah botol dan direndam dalam saliva buatan kemudian disimpan dalam incubator. Mahkota dan akar gigi,kemudian ditanam dalam resin akrilik sesuai kelompok sebelumnya dengan permukaan bukal menghadap ke atas. Semua sampel diuji kekerasannya dengan uji kekerasan Vickers menggunakan beban 100 g selama 15 detik. Permukaan bukal menghadap ke atas, kemudian dijepit dengan alat penjepit pada meja alat Micro Vickers Hardness Tester. Sampel diatur sedemikian rupa sehingga akan terlihat gambar yang dapat diukur panjang diagonalnya langsung dengan micrometer yang ada pada lensa okuler. Nilai kekerasan email dalam Vickers hardness number (VHN) juga dapat diperoleh dari table setelah mengetahui rata-rata panjang diagonal, berat badan yang digunakan dan waktu yang digunakan untuk uji kekerasan. Pengujian ini dilakukan pada setiap kelompok. Selanjutnya diuji dengan uji-t. hasil penelitian menunjukkan ada perbedaan yang bermakna antara aplikasi ultraEZ lima menit dibandingkan tanpa aplikasi ultraEZ terhadap kekerasan email pada p>0,05. Background. One of the side effect of bleaching agent is a dentine hypersensitive and ultraEZ is an agent can diminish this process. The purpose of this study was to evaluate difference of enamel microhardness post external bleaching with or without ultra-eze application. Method. Twenty extracted permanent bicuspid used in this study were divided into two group, each group contains 10 bicupids. Group I was treated external bleaching without ultra-eze application and group II was treated external bleaching with application ultraEZ for five minutes. After that all of the subject were seaked the artificial saliva and kept in the incubator 24 hours. Teeth were embedded into acrylic resin with the buccal sirface facing up. Further all of the subject was evaluated by Vickers using 100 g load for 15 seconds. Teeth were stapled on the Micro Hardness Tester table diagonal of emage was measure using micrometer attach on ocular lesnse. Email hardness can be known after calculating, the everage diagonal length, the load used and the duration of hardness test. Further the data was analize using t-test. The result shows there is significant difference between bleaching with and without the application of ultra-eze.

scholarly journals COMPARISON OF SALT BATH PREOXIDATION AND AIR PREOXIDATION FOR SALT BATH NITRIDING

2019 ◽  
Vol 25 (2) ◽  
pp. 130
Author(s):  
Wenchen Mei ◽  
Jiqiang Wu ◽  
Mingyang Dai ◽  
Kunxia Wei ◽  
Jing Hu
Keyword(s):  
Compound Layer ◽  
Salt Bath ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tester ◽  
Modified Surface ◽  
Salt Bath Nitriding ◽  
Modified Surface Layer

<p class="AMSmaintext1">Salt bath preoxidation was primarily conducted prior to salt bath nitriding, and the effect on salt bath nitriding was compared with that of conventional air preoxidation. Characterization of the modified surface layer was made by means of optical microscopy, scanning electron microscope (SEM), micro-hardness tester and x-ray diffraction (XRD). The results showed that the salt bath preoxidation could significantly enhance the nitriding efficiency. The thickness of compound layer was increased from 13.3μm to 20.8μm by salt bath preoxidation, more than 60% higher than that by conventional air preoxidation under the same salt bath nitriding parameters of 560℃ and 120min. Meanwhile, higher cross-section hardness and thicker effective hardening layer were obtained by salt bath preoxidation, and the enhancement mechanism of salt bath preoxidation was discussed.</p>

Effect of Laser Peening on Residual Stress and Micro-Hardness of TC4 Titanium Alloy

2013 ◽  
Vol 341-342 ◽  
pp. 246-250
Author(s):  
Hong Chao Qiao ◽  
Ji Bin Zhao ◽  
Yi Xiang Zhao ◽  
Lun Li
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Layer Thickness ◽  
Pulse Energy ◽  
Work Piece ◽  
Laser Peening ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Hardness Tester ◽  
Tc4 Titanium Alloy

Laser peening offers potential advantages over conventional peen technologies in terms of the depth of the residual stresses that can be induced, and improvements in surface micro-hardness. The present study was undertaken to understand the effect of laser penning on the properties of titanium alloy, a TC4 titanium alloy work-piece was processed with ND: YAG laser with the wavelength of 1064 nm, pulse energy of 0-10J and pulse width of 12ns, and micro-hardness and residual stress for different laser peening parameters were examined and analyzed by micro-hardness tester and X-ray diffraction. Results are presented and discussed of the residual stress profiles and the micro-hardness profiles, The experimental results show that the satisfying laser peening appearance can be achieved when the pulse energy was 6J, water tamping layer thickness was 1.8mm and ablative layer thickness was 100μm, surface micro-hardness increased by up to 33% and the compressive residual stress on the surface of laser shocked area reached up to-327.8MPa, laser peening improved hardness and residual stress of titanium alloy significantly. The experiment results show that the effect of laser peening was evidently.

Characterization on Duplex Treated Coating Fabricated by Laser Cladding and Active Screen Plasma Nitriding

2011 ◽  
Vol 69 ◽  
pp. 93-98
Author(s):  
Xiao Dong Zhang ◽  
Bin Shi Xu ◽  
Shi Yun Dong ◽  
Zhi Jian Wang ◽  
Han Shan Dong ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Plasma Nitriding ◽  
White Layer ◽  
Surface Hardness ◽  
Nitrogen Diffusion ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Hardness Tester ◽  
Active Screen Plasma Nitriding ◽  
Active Screen

In order to enhance the performances of laser remanufacturing part, we combined laser cladding with active screen plasma nitriding duplex treatment to repair metal part. The microstructure, phase structure and micro-hardness of duplex treated coating were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and micro-hardness tester. Wear tests were carried out on reciprocating wear tester under dry sliding condition. The results show that the white layer and the nitrogen diffusion layer were formed after nitriding treatment. The duplex treated coating consists mainly of γ-Fe, CrN, Fe4N and Fe3N. The duplex treated coating improved not only surface hardness but also wear resistance.

Microstructures and Properties of W-26Re Alloy by SPS

2012 ◽  
Vol 236-237 ◽  
pp. 113-117
Author(s):  
Song Wang ◽  
Ming Xie
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Test Results ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tester ◽  
Fine Grain ◽  
Plasma Sintering ◽  
Spark Plasma

W-26Re alloy was fabricated by spark plasma sintering (SPS) technology. The phases, microstructures and mechanical properties of the alloy were investigated by X-ray diffraction, optical light microscope, scanning electron microscope, energy dispersion spectroscope, digital display micro-hardness tester and tensile test. Results show that, using SPS technique can prepare W-26Re alloy with high density, fine grain and excellent mechanical properties. The relative density of W-26Re alloy was 96.2%. The main phases in the alloy were determined by the amount of (W) solid solution and the intermetallic  phases. The micro-hardness was 729HV, the ultimate tensile strength was 1680MPa, yield tensile strength was 1143MPa and elongation of alloy was 8.7%.

The Crystallinity and Hardness Properties of Al-Cu/SiCp New Composite Materials

2012 ◽  
Vol 576 ◽  
pp. 450-453
Author(s):  
A. Arifutzzaman ◽  
Md Abdul Maleque ◽  
D. Sujan
Keyword(s):  
Composite Materials ◽  
Hardness Test ◽  
Stir Casting ◽  
X Ray Diffraction ◽  
X Ray ◽  
Casting Technique ◽  
Hardness Tester ◽  
Transmission Technique ◽  
The Matrix ◽  
Diamond Paste

The main aim of this paper is to investigate the crystallinity and hardness properties of Al-Cu/SiCp matrix composite (AMC) materials. The materials were prepared using a noble stir casting technique by varying the percentage of Cu in the Al-Cu matrix. Qualitative X-ray analysis has been carried out to characterize the crystallinity of the Al-Cu/SiCp as-cast composite materials. Sample was cut and shaped into 25 mm×15 mm×4 mm in dimension then polished with diamond paste. X-ray diffraction diagrams were recorded using a transmission technique with a SHIMADZU Lab X (XRD-6000) X-ray generator operating at Cu Kα1 radiation. Hardness test was conducted using Vickers hardness tester (Mitutuyo, MVK-H2). The results indicated that a significant crystal growth was occurred in the composite materials due to increase of Cu from 2 to 4 % whereas a slight improvement of crystallinity was observed when the Cu percentage was increased from 4 to 6 % in the matrix. It was also revealed from the result that a similar trend was grasped in hardness increment with the crystallinity of Al-Cu/SiCp AMCs.

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