The Influence of Spraying Parameters on Stresses and Mechanical Properties of HVOF-Sprayed Co-Cr-W-C Coatings

2014 ◽  
Vol 606 ◽  
pp. 171-174 ◽  
Author(s):  
Jiří Matějíček ◽  
Šárka Houdková ◽  
Olga Bláhová ◽  
Zdenek Pala
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Particle Temperature ◽  
Instrumented Indentation ◽  
Stellite 6 ◽  
Young’S Moduli ◽  
Particle Characteristics ◽  
Spraying Parameters ◽  
The Relationship

Stellite 6 Co-Cr-W-C coatings were sprayed by HVOF while systematically varying the spraying parameters, namely the equivalent ratio and combustion pressure. During spraying, the in-flight particle temperature and velocity were measured. Deposition, thermal and residual stresses were determined by in-situ curvature monitoring of the sprayed samples. Young's moduli and hardness of the coatings were determined by instrumented indentation. The relationship between spraying parameters, in-flight particle characteristics and mechanical properties is discussed.

Design of Novel Treated Silica Xerogels: Synthesis, Property and Reinforcement in Silicone Elastomers

1998 ◽  
Vol 520 ◽  
Author(s):  
Q. Deng ◽  
G. T. Bums ◽  
J. R. Hahn ◽  
C. C. Reese ◽  
J. D. Preston ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Area ◽  
Silica Xerogels ◽  
Silicone Elastomers ◽  
Surface Areas ◽  
Reinforcing Fillers ◽  
Controlled Porosity ◽  
The Relationship ◽  
Filler Structure

ABSTRACTTreated silica xerogels with controlled porosity and surface area were prepared by the in-situ treatment of hydrogels with hexamethyldisiloxane in the presence of isopropyl alcohol. The resulting hydrogels were hydrophobic and readily transferred to organic solvents allowing their isolation. The surface area and porosity of the xerogel were controlled by varying the pH, time and temperature used to aggregate the hydrogel prior to treatment. The treated xerogels were evaluated as reinforcing fillers in silicone rubber formulations. When the bases were crosslinked with peroxides, silicone elastomers with acceptable mechanical properties were obtained. The relationship between the surface area, porosity and the type and degree of surface treatment of the xerogel, and its reinforcing ability was studied. In general, the mechanical properties of the elastomer increased as the filler structure increased; however, xerogels with higher surface areas were more difficult to incorporate and gave higher plasticity bases.

Mechanical Properties Of Cu-Based Composites with in Situ Formed Ultrafine Filaments

1981 ◽  
Vol 12 ◽  
Author(s):  
J. Bevk ◽  
W. A. Sunder ◽  
G. Dublon ◽  
David E. Cohen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Young’S Modulus ◽  
Size Dependence ◽  
Young's Modulus ◽  
Plastic Properties ◽  
Young’S Moduli ◽  
Lattice Softening

ABSTRACTElastic and plastic properties of in situ Cu-based composites with Nb, V, and Fe filaments are reviewed. The evidence is presented for a pronounced size dependence of both the ultimate tensile strength and the Young's moduli. In composites with the smallest filaments (d∼50–200Å) and filament densities as high as 1010/cm2 dislocation density reaches values of 1013 cm/cm3. The yield stress of these samples increases dramatically over the predictions based on the “rule of mixtures” and their ultimate tensile strength approaches the estimated theoretical strength of the material (∼2.7GPa). The observed decrease of Young's modulus as a function of inverse wire diameter in the as-drawn composites is attributed to lattice softening due to high density of extended lattice defects. Upon annealing, Young's modulus increases by as much as 100% and exceeds the maximum values calculated from bulk elastic constants. Possible mechanisms leading to modulus enhancement and to related changes in magnetic and superconducting behavior of in situ composites are discussed.

Physical and Mechanical Properties of Mullite-Whisker Reinforced Alumina Composites

2007 ◽  
Vol 334-335 ◽  
pp. 325-328 ◽  
Author(s):  
Wei Kong Pang ◽  
Nobuo Tezuka ◽  
It Meng Low ◽  
E.G. Mehrtens ◽  
Bruno A. Latella
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Hot Isostatic Pressing ◽  
Physical And Mechanical Properties ◽  
Reaction Sintering ◽  
Alumina Matrix ◽  
Young’S Moduli ◽  
Solid Density ◽  
Alumina Composites

Reaction sintering and hot-isostatic-pressing (HIP) have been used for the compaction and densification of mullite-whisker-reinforced alumina composites. The effect of alumina matrix constraints on the in-situ transformation sequence in alumina-halloysite-AlF3 system was studied using differential thermal analysis. The physical and mechanical properties of the HIPed samples have been characterized in terms of bulk density, apparent solid density, porosity, Young’s moduli, flexural strength, hardness and the fracture toughness.

Application of a portable indentation rig with Rockwell indenter to determine mechanical properties and residual stresses on an aluminum plate

2020 ◽  
Vol 55 (7-8) ◽  
pp. 246-257
Author(s):  
Saba Salmani Ghanbari ◽  
Amir-Hossein Mahmoudi
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Indentation Load ◽  
Instrumented Indentation ◽  
Unknown Parameters ◽  
Plastic Properties ◽  
Wide Range ◽  
Portable Apparatus ◽  
Non Destructive

Measuring residual stresses is still a dilemma in many engineering applications. It is even more crucial when the industrial requirements demand for a non-destructive technique in order to avoid compromising the structural integrity of the engineering components. Furthermore, estimating the mechanical properties of the materials, especially when the components are aged, is of importance. Instrumented indentation has gained much interest in recent years. There are many studies in the literature which are focused on measuring residual stresses or mechanical properties using instrumented indentation. Since in many cases there is no possibility of transferring large samples or those under service, for possible measurements, having a portable rig can be very useful. Furthermore, indentation procedure is a low-cost non-destructive method with high accuracy which is able to measure the plastic properties of material as well as its residual stresses on which the designing and construction of the portable apparatus were based. The instrumented indentation testing details were followed according to the ASTM E2546-15 standard practice. In this research, a wide range of simulations were performed on a group of aluminum alloys in order to estimate the equi-biaxial residual stresses by analyzing the indentation load–displacement curves which were obtained from the experimental outcomes. Then neural networks were employed to estimate the unknown parameters. The performance accuracy of the designed portable apparatus and the acceptable precision of the introduced method were then verified with experimental tests performed on Al 2024-T351.

scholarly journals Mechanical Properties of Zr–Si–N Films Fabricated through HiPIMS/RFMS Co-Sputtering

Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 263 ◽  
Author(s):  
Li-Chun Chang ◽  
Yu-Zhe Zheng ◽  
Yung-I Chen
Keyword(s):  
Mechanical Properties ◽  
Residual Stresses ◽  
Magnetron Sputtering ◽  
Radio Frequency ◽  
High Hardness ◽  
Face Centered Cubic ◽  
Young’S Moduli ◽  
Face Centered ◽  
Si Content ◽  
Compressive Residual Stresses

Zr–Si–N films were fabricated through the co-deposition of high-power impulse magnetron sputtering (HiPIMS) and radio-frequency magnetron sputtering (RFMS). The mechanical properties of the films fabricated using various nitrogen flow rates and radio-frequency powers were investigated. The HiPIMS/RFMS co-sputtered Zr–Si–N films were under-stoichiometric. These films with Si content of less than 9 at.%, and N content of less than 43 at.% displayed a face-centered cubic structure. The films’ hardness and Young’s modulus exhibited an evident relationship to their compressive residual stresses. The films with 2–6 at.% Si exhibited high hardness of 33–34 GPa and high Young’s moduli of 346–373 GPa, which was accompanied with compressive residual stresses from −4.4 to −5.0 GPa.

Fabrication of Ti2AlC/TiAl Composites with the Addition of Niobium by Spark Plasma Sintering

2008 ◽  
Vol 368-372 ◽  
pp. 1004-1006 ◽  
Author(s):  
Yun Long Yue ◽  
H.T. Wu
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Three Point Bending ◽  
Plasma Sintering ◽  
Titanium Aluminum ◽  
Spark Plasma ◽  
The Difference ◽  
The Relationship

Ti2AlC/TiAl composites with the addition of niobium were prepared by spark plasma sintering using titanium, aluminum, niobium elemental powers and TiC particles as reactants. The experimental and analytical studies on this kind of material concentrated on the relationship between reinforcement phase and mechanical properties. The Ti2AlC/TiAl composites with 5% niobium exhibit high mechanical properties. The three-point bending strength and fracture toughness reaches as high as 915MPa and 23 MPa·m1/2, respectively. It is found that the in-situ reaction occurs at 1100°C with the addition of niobium at the interface between the TiAl matrix and original reinforcement TiC. Further XRD results indicate that the difference in the reinforcement phase from TiC to Ti2AlC is one of the most important origins to the variation in mechanical properties.

scholarly journals Joining Alumina and Sapphire by Growing Aluminium Borate Whiskers In-Situ, and the Whiskers’ Orientation Relationship with the Sapphire Substrate

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 175 ◽  
Author(s):  
Chun Li ◽  
Xiaoqing Si ◽  
Shuang Wu ◽  
Junlei Qi ◽  
Yongxian Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Orientation Relationship ◽  
Sapphire Substrate ◽  
Great Influence ◽  
The Other ◽  
Aluminium Borate ◽  
Random Growth ◽  
The Relationship ◽  
Scanning Electron

Bonding between polycrystal alumina and sapphire with (0001), (10 1 ¯ 0), (11 2 ¯ 0), (1 1 ¯ 02) orientations is successfully achieved by growing aluminium borate whiskers in the joint. The morphology of the whiskers in the joint is characterised by (Scanning Electron Microscopy) SEM. The relationship between the growing direction of the aluminium borate whiskers and the orientation of the sapphire substrate is investigated. The effect of the growing direction of the aluminium borate whiskers on the mechanical properties of the joint is discussed. The results show that the whiskers on the sapphire with (10 1 ¯ 0) orientation grow perpendicular to the surface of the substrate while the whiskers show a random growth on the other substrates. It is found that there is an orientation relationship between the whiskers (220) and sapphire (10 1 ¯ 0) and the morphology of the whiskers has great influence on the mechanical properties of the joint. The joint between polycrystal alumina and sapphire with (10 1 ¯ 0) orientation exhibits the highest strength, which reaches 26 MPa.

scholarly journals Determination of Young’s modulus of Sb2S3 nanowires by in situ resonance and bending methods

2016 ◽  
Vol 7 ◽  
pp. 278-283 ◽  
Author(s):  
Liga Jasulaneca ◽  
Raimonds Meija ◽  
Alexander I Livshits ◽  
Juris Prikulis ◽  
Subhajit Biswas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Cross Section ◽  
Young's Modulus ◽  
Cross Sectional ◽  
Bending Tests ◽  
Young’S Moduli ◽  
Increasing Trend

In this study we address the mechanical properties of Sb2S3 nanowires and determine their Young’s modulus using in situ electric-field-induced mechanical resonance and static bending tests on individual Sb2S3 nanowires with cross-sectional areas ranging from 1.1·104 nm2 to 7.8·104 nm2. Mutually orthogonal resonances are observed and their origin explained by asymmetric cross section of nanowires. The results obtained from the two methods are consistent and show that nanowires exhibit Young’s moduli comparable to the value for macroscopic material. An increasing trend of measured values of Young’s modulus is observed for smaller thickness samples.

Residual Stresses and Young's Moduli of Plasma Sprayed W+Cu Composites and FGMs Determined by In Situ Curvature Method

2014 ◽  
Vol 606 ◽  
pp. 151-154 ◽  
Author(s):  
Jiří Matějíček ◽  
Radek Mušálek ◽  
Pavel Chráska
Keyword(s):  
Residual Stresses ◽  
Functionally Graded ◽  
Young’S Moduli ◽  
Water Stabilized Plasma ◽  
Graded Material ◽  
History Of ◽  
Coating Formation ◽  
Entire History ◽  
Plasma Sprayed

In this work, application of the in-situ curvature method on plasma sprayed composite and graded coatings is presented. First, uniform composites of different W/Cu ratio, were sprayed by water stabilized plasma. By continuous monitoring of the curvature of a flat specimen during spraying, the stress evolution throughout the entire history of coating formation was traced. By a simultaneous monitoring of curvature and temperature during post-deposition cooling, Youngs moduli of the coatings were determined. Second, a 5-layer stepwise functionally graded material (FGM) was sprayed. With the knowledge of each layers properties, the complex evolution of deposition, thermal and residual stresses in the FGM could be determined. The ability to determine the stresses and mechanical properties with a spatial resolution comparable to the thickness of one spray pass is demonstrated.

Analysis of Residual Stress Generated During Plasma Spraying of Glass Coatings

1998 ◽  
Author(s):  
Y. Bao ◽  
T. Zhang ◽  
D.T. Gawne
Keyword(s):  
Residual Stress ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Residual Stresses ◽  
Plasma Spraying ◽  
Experimental Measurements ◽  
Plasma Flame ◽  
Spraying Parameters

Abstract An investigation has been undertaken on the analysis of residual stress in glass coatings during plasma spraying. Theoretical analysis and in-situ experimental measurements show that the residual stresses in glass coatings are particularly sensitive to the heat input from the plasma flame, since this can raise the temperature to above the glass transition temperature. Control of the spraying parameters enables the quench stress of splats to be relaxed by the end of the spraying and the only significant remaining source of stress derives from the differential contraction between the coating and substrate during cooling. The analysis also shows that a stress transition occurs during cooling and that the sign of the final residual stress depends upon the expansion coefficient of the glass. The residual stresses are shown to govern the critical coating thickness for cracking and the coating adhesion.

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