scholarly journals Application of the plasticity characteristic determined by the indentation technique for evaluation of mechanical properties of coatings: I. specific features of the test method procedure

2004 ◽  
Vol 36 (1) ◽  
pp. 27-41 ◽  
Author(s):  
A.V. Byakova ◽  
Yu.V. Milman ◽  
A.A. Vlasov
Keyword(s):  
Mechanical Properties ◽  
Indentation Load ◽  
Test Method ◽  
Simplified Model ◽  
Micro Hardness ◽  
Properties Of Coatings ◽  
Modified Model ◽  
Plasticity Characteristic ◽  
Measurement Results ◽  
Hardness Values

Specific features of the test method procedure capable for determining the plasticity characteristic dH by indentation of inhomogeneous coatings affected by residual stress was clarified. When the value of the plasticity characteristic for coating was found to be as great as dH > 0.5 a simplified model was found to be reasonably adequate, while a modified model assumed compressibility of the deformation core beneath indentation. The advantage of the modified approach compared to the simplified one was grounded experimentally only if the elastic deformation for coating becomes greater than ?e ? 3.5%, resulting in the decrease of plasticity characteristic dH < 0.5. To overcome non accuracy caused by the effect of the scale factor on measurement results a comparison of different coatings was suggested using stabilized values of the plasticity characteristic dH determined under loads higher than critical, P ? Pc, ensuring week dependence of micro hardness values on the indentation load.

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.

scholarly journals Experimental Evaluation of Mechanical Properties of Friction Welded Dissimilar Steels under Varying Axial Pressures

2016 ◽  
Vol 66 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Amit Handa ◽  
Vikas Chawla
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Failure Analysis ◽  
Friction Welding ◽  
Experimental Evaluation ◽  
Micro Hardness ◽  
Aisi 304 ◽  
Torsional Strength ◽  
Hardness Values

AbstractThe present study emphasizes on joints two industrially important materials AISI 304 with AISI 1021steels, produced by friction welding have been investigated. Samples were welded under different axial pressures ranging from 75MPa to 135MPa, at constant speed of 920rpm. The tensile strength, torsional strength, impact strength and micro hardness values of the weldments were determined and evaluated. Simultaneously the fractrography of the tensile tested specimens were carried out, so as to understand the failure analysis. It was observed that improved mechanical properties were noticed at higher axial pressures. Ductile failures of weldments were also observed at 120MPa and 135MPa axial pressures during fractography analysis.

scholarly journals Performance of MoS2/Zr Composite Coatings at Different Deposition Temperatures

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5100
Author(s):  
Wenlong Song ◽  
Kai Sun ◽  
Guangming Zhao ◽  
Long Zhu ◽  
Shoujun Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Deposition Temperature ◽  
Adhesion Force ◽  
Composite Coatings ◽  
Hardened Steel ◽  
Dry Sliding ◽  
Micro Hardness ◽  
Properties Of Coatings ◽  
Mechanical And Tribological Properties ◽  
Deposition Technology

The properties of the MoS2/Zr coatings can be significantly affected by the deposition temperature. In this study, the MoS2/Zr composite coatings were fabricated on the cemented carbide surface, utilizing the duplex deposition technology at various deposition temperatures. The effects of deposition temperature on the mechanical and friction properties of the MoS2/Zr coatings were systematically studied. Results exhibited that as the deposition temperature increased, the adhesion force increased first and then decreased, and the coating thickness and micro-hardness gradually increased. Dry sliding tests against a hardened steel ring showed that the tribological behaviors and wear mechanisms of the MoS2/Zr coatings varied with deposition temperature, which were due to the changing mechanical properties of coatings caused by the temperature. The coatings deposited at a temperature of 180 °C and 200 °C possessed preferable comprehensive mechanical and tribological properties.

scholarly journals Effect of Beta Low Irradiation Doses on the Filled PA66 Measured by Micro-Indentation Test

2014 ◽  
Vol 1025-1026 ◽  
pp. 415-418
Author(s):  
Martin Ovsik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Martin Reznicek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Fibers ◽  
Indentation Test ◽  
Radiation Doses ◽  
Micro Hardness ◽  
Polyamide 66 ◽  
Depth Sensing ◽  
Micro Indentation ◽  
Hardness Values ◽  
Different Doses

The presented article deals with the research of micro-mechanical properties in the surface layer of modified Polyamide 66 filled by 30% of glass fibers. These micro-mechanical properties were measured by the Depth Sensing Indentation - DSI method on samples which were non-irradiated and irradiated by different doses of the β - radiation. Radiation doses used were 0, 15, 30 and 45 kGy for filled Polyamide 66 with the 6% cross-linking agent (triallyl isocyanurate). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the polyamide 66 tested. The highest values of micro-mechanical properties were reached at radiation dose of 30 kGy, when the micro-hardness values increased by about 64%. The aim of the article is to find out the influence of the radiation on the micro-hardness of the modified glass fiber-filled Polyamide 66 (PA66).

Evaluation and comparison the effect of heat treatment on mechanical properties of NiCrBSi thermally sprayed coatings

2018 ◽  
Vol 65 (1) ◽  
pp. 34-37
Author(s):  
Mohsen Shabanlo ◽  
Reza Amini Najafabadi ◽  
Amirhossein Meysami
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Test ◽  
Flame Spray ◽  
Micro Hardness ◽  
Post Heat Treatment ◽  
Properties Of Coatings ◽  
Content Type ◽  
Sprayed Coatings ◽  
Thermal Sprayed Coatings

Purpose This study aims to investigate the effect of post heat treatment on mechanical properties of NiCrBSi coatings, which were applied on 316L stainless steel using high-velocity oxygen-fuel (HVOF) and flame spray techniques. Design/methodology/approach The properties of coatings were investigated by metallographic characterizations as well as wear, micro-hardness and adhesion tests. Findings The micro-hardness results showed that the coatings considerably increased the sub-layer hardness. In addition, regarding the wear test results, it can be seen that heat treatment increased wear resistance of the coatings. These thermal sprayed coatings are usually re-melted by post heat treatment, leading to improvement in tribological properties. The results obtained revealed that re-melting procedure improved the metallurgical bonding in the substrate\coating interface. Originality/value Microstructure defects resulting from thermal spraying such as pores and unmelted particles can be eliminated by post heat treatment. This process can considerably improve the corrosion and wear resistances of the thermal sprayed coatings.

Effects of Different Preparation Parameters on the Properties of MAO Coatings

2014 ◽  
Vol 609-610 ◽  
pp. 14-19 ◽  
Author(s):  
Xin Wu ◽  
Qing Min Liu ◽  
Hong Xia Li
Keyword(s):  
Mechanical Properties ◽  
Growth Rate ◽  
Wear Resistance ◽  
Current Density ◽  
Ceramic Coating ◽  
Electrolyte Concentration ◽  
Measurement Properties ◽  
Micro Hardness ◽  
Micro Arc Oxidation ◽  
Hardness Values

Effects of different preparation parameters on the structural and mechanical properties of micro-arc oxidation coatings prepared in silicate electrolyte on 6063 alloy were investigated. The results show that the growth rate of ceramic coating increases with increasing current density and electrolyte concentration. The prepared coating had denser and smoother surface with few defects, higher micro-hardness values and better wear resistance when the current density was increased to 20A/dm2. The measurement properties were all up to their optimum values when the electrolyte concentration was in the range of 9-12g/l and oxidation time was 60min, respectively.

Micro-Hardness Test of Cross-Linking LLDPE

2017 ◽  
Vol 1142 ◽  
pp. 134-137
Author(s):  
Martin Ovsik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Vaclav Janostik
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Hardness Test ◽  
Cross Linking ◽  
Radiation Doses ◽  
Micro Hardness ◽  
Depth Sensing ◽  
Linear Polyethylene ◽  
Hardness Values ◽  
Different Doses

The presented article deals with the research of micro-mechanical properties in the surface layer of modified linear polyethylene (LLDPE). These micro-mechanical properties were measured by the Depth Sensing Indentation - DSI method on samples which were non-irradiated and irradiated by different doses of the β - radiation (0, 66, 132 and 198 kGy ). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LLDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 132 kGy, when the micro-hardness values increased by about 29%. These results indicate advantage crosslinking of the improved mechanical properties.

The critical role of boron doping in the thermoelectric and mechanical properties of nanostructured α-MgAgSb

2018 ◽  
Vol 6 (36) ◽  
pp. 9821-9827 ◽  
Author(s):  
Weihong Gao ◽  
Xiaoyang Yi ◽  
Bo Cui ◽  
Zhenyou Wang ◽  
Jin Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Valence Band ◽  
Critical Role ◽  
Boron Doping ◽  
Thermoelectric Performance ◽  
Micro Hardness ◽  
Solution Strengthening ◽  
Hardness Values

The ineffectiveness of boron doping to enhance thermoelectric performance lied in the introduced perturbation to the valence band. Due to the significant solution strengthening by boron doping, the micro-hardness values of α-MgAgSb have been largely increased.

scholarly journals Annealing Effect on Structural, Thermal and Mechanical Properties of the Binary Al 85 Ni15 Alloy Composition

2019 ◽  
Vol 7 (1) ◽  
pp. 1-8
Author(s):  
Sarwar Ibrahim Saleh ◽  
Musa Gögebakan ◽  
M. S. Omar ◽  
Hakan Yaykasli ◽  
Celal Kursun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Alloy System ◽  
Hardness Measurement ◽  
Annealing Effect ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Arc Melting ◽  
Heat Treated ◽  
Measurement Results ◽  
Melting Technique

Introduction: The Al 85-Ni15 alloy with 99.99% purity of Al and Ni were prepared by an arc melting technique system. The annealing effect onthe microstructure properties, phase transformation and micro-hardness for the Al-Ni alloy system were investigated. Material and Methods:The alloys were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Differential Thermal Analysis (DTA) as well as Vickers micro-hardness measurement. Results and Discussion: The quantitative results confirm that the chemical composition of the alloys is very close to compositions and the microstructures are in typical lamellar morphology. Mechanical properties for the as-prepared samples and subsequently heat-treated samples were measured by a Vickers indenter. Values of the micro-hardness (HV) Conclusions: According the XRD pattern analysis a multi phases produced, such as Al, AlNi3in room temperature, Al3Ni2, Al0.42Ni0.58 at 200ºC, Al1.1Ni0.9 at 300ºC and Al 0.802Ni0.198, AlNi3 and AlNi at 400ºC, and Al0.802Ni0.198, AlNi3 and AlNi for 500ºC. Similar approached were obtained from the results of SEM and DTA measurements. Annealing treatments are visibly affecting the alloy phase formation with different phases at different temperature. and the elastic modulus (E) of the as prepared sample are 132.9±0.1 kgfmm-2 (1.329±0.1 GPa) and 80.340±0.1 GPa, respectively. Furthermore, the characteristic of the materials plasticity (δH) value was calculated to be 0.85. The micro-hardness values are decrease with the increase of annealing temperatures.

Syntheses and Mechanical Properties of Ti-Al-Si-C-N Coatings by a Hybrid Coating System

2008 ◽  
Vol 569 ◽  
pp. 105-108
Author(s):  
Eun Young Choi ◽  
Ji Hoon Park ◽  
Kwang Ho Kim
Keyword(s):  
Mechanical Properties ◽  
Hybrid Coating ◽  
Coating System ◽  
Micro Hardness ◽  
Microstructure Characteristics ◽  
Composite Microstructure ◽  
Si Content ◽  
Hardness Values ◽  
Amorphous Si3n4 ◽  
Si Wafer

In this work, the Ti-Al-Si-C-N coatings were synthesized on Stainless steel and Si wafer by a hybrid coating system, where arc ion plating (AIP) technique was combined with a magnetron sputtering technique. Also, the effect of Si content on the microstructure and mechanical properties of Ti-Al-C-N coatings were systematically investigated. The Ti-Al-Si-C-N coatings characterized by a nanocomposite comprising nano-sized Ti-Al-C-N crystallites embedded in amorphous Si3N4 phase. The micro-hardness values of Ti-Al-Si-C-N coatings were largely depended on Si content and the micro-hardness value of Ti-Al-Si-C-N coatings significantly increased from 38Gpa of Ti-Al-C-N coatings to approximately 56 GPa with the addition Si content of 9.8 at.%. The enhanced hardness values of Ti-Al-Si-C-N coatings were explained with the refinement of Ti-Al-C-N crystallites and composite microstructure characteristics by the percolation of amorphous Si3N4/SiC phase. The average friction coefficient of Ti-Al-Si-C-N decreased from 0.6 of Ti-Al-C-N to 0.23 with increasing the Si content up to 15.3 at. %. The decreased friction coefficients of Ti-Al-Si-C-N coatings was elucidated by the formation of SiO2 or Si(OH)2 layer known as self-lubricant materials.

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