Effect of Phase Transformation on the Wear Behavior of NiTi Alloy

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
M. Abedini ◽  
H. M. Ghasemi ◽  
M. Nili Ahmadabadi ◽  
R. Mahmudi
Keyword(s):  
Wear Behavior ◽  
Niti Alloy ◽  
Testing Temperature ◽  
Compression Tests ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Mechanical And Tribological Properties ◽  
Ni Alloy ◽  
Shape Memory Effects ◽  
Pin On Disk

In this paper, mechanical and tribological properties of a Ti-50.3 at % Ni alloy were investigated. The transformation temperatures of the alloy were determined using differential scanning calorimetry. Three-point bending tests were performed to characterize the pseudoelasticity and shape memory effects. Uni-axial compression tests were also performed at different testing temperatures. The wear tests were conducted using a pin-on-disk tribometer at testing temperatures ranging from 0°C to 80°C. The wear results showed that with increasing the testing temperature from 0°C to 50°C, the wear of the alloy was decreased, which could be attributed to the higher pseudoelasticity of the alloy at a testing temperature of 50°C. The pseudoelasticity of the alloy decreased at a higher testing temperature of 80°C; however, its wear resistance increased considerably due to higher ultimate strength and work hardening.

Effect of Precipitates on Mechanical and Tribological Performance of AZ91 Magnesium Alloy–Steel Couple

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Deepak Kumar ◽  
Jayant Jain ◽  
Tulsi Bisht ◽  
Anuz Zindal
Keyword(s):  
Magnesium Alloy ◽  
Wear Behavior ◽  
Tribological Performance ◽  
Az91 Alloy ◽  
Az91 Magnesium Alloy ◽  
Mechanical And Tribological Properties ◽  
Mg17al12 Phase ◽  
Az91 Magnesium ◽  
Steel Aisi ◽  
Pin On Disk

The present work involves the study of the effect of precipitates on mechanical and tribological properties of AZ91 magnesium alloy. Optical microscopy, scanning electron microscopy (SEM), and nanoindentation were used to characterize the microstructures and mechanical properties of the alloy. In addition, the wear behavior of the alloy was deduced using a pin-on disk tribological configuration under unidirectional sliding against steel (AISI 250). The elastic modulus of AZ91 alloy was found to vary significantly with changing precipitation state. The tribological evaluations showed that the specific wear-rate of solutionized sample is lowest as compared to the aged samples. This was attributed to the absence of γ-Mg17Al12 phase. Examination of worn surfaces suggested that microploughing coupled with the adhesive mode of wear is the main wear mechanism in the aged samples.

scholarly journals Synthesis of Niti Based Nanocomposites Reinforced by Ha Addition

2016 ◽  
Vol 61 (2) ◽  
pp. 577-580 ◽  
Author(s):  
K. Niespodziana ◽  
K. Jurczyk ◽  
M. Jurczyk
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Shape Memory ◽  
Vickers Hardness ◽  
Niti Alloy ◽  
Weight Ratio ◽  
Niti Shape Memory Alloy ◽  
Scanning Calorimetry ◽  
Alloy Matrix ◽  
Shape Memory Effects

Abstract NiTi alloy is well known for its unique properties, such as good ductility at room temperature, good corrosion resistance and also thermal shape memory effects. On the other hand hydroxyapatite has a combination of desirable properties, such as low density and excellent compatibility with the bone which used as ceramic reinforced phases can change the properties and thermal stability of the NiTi alloy. In this study, the NiTi alloy matrix shape memory composite reinforced by hydroxyapatite particles was successfully fabricated using mechanical alloying and powder metallurgical process. The structural evaluation of milled and heat treated powders was studied by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The differential scanning calorimetry was used to measure the phase transformation temperatures. The porosity, Vickers’ hardness and corrosion resistance of the TiNi-HA composites were investigated. The results show that the increase of the weight ratio of hydroxyapatite causes increase the porosity and decrease the corrosion resistance. The fabricated NiTi alloy matrix composite possesses lower density and higher Vickers’ hardness as the pure NiTi shape memory alloy, yet still exhibiting the shape memory effect.

Mechanical and thermal characterization of grafted PP-NCC nanocomposites

2019 ◽  
pp. 089270571987822
Author(s):  
Saud Aldajah ◽  
Mohammad Y Al-Haik ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik
Keyword(s):  
Thermal Properties ◽  
Interfacial Adhesion ◽  
Thermal Characterization ◽  
Mechanical And Thermal Properties ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Twin Screw ◽  
Thermal Stability Of

This study reveals the enhancement of mechanical and thermal properties of maleic anhydride-grafted polypropylene (PP- g-MA) with the addition of nanocrystalline cellulose (NCC). A nanocomposite was manufactured by blending various percentages of PP, MA, and NCC nanoparticles by means of a twin-screw extruder. The influence of varying the percentages of NCC on the mechanical and thermal behavior of the nanocomposite was studied by performing three-point bending, nanoindentation, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy tests. The novelty of this study stems on the NCC nanoparticles and their ability to enhance the mechanical and thermal properties of PP. Three-point bending and nanoindentation tests revealed improvement in the mechanical properties in terms of strength, modulus, and hardness of the PP- g-MA nanocomposites as the addition of NCC increased. SEM showed homogeneity between the mixtures which proved the presence of interfacial adhesion between the PP- g-MA incorporated with NCC nanoparticles that was confirmed by the FTIR results. DSC and TGA measurements showed that the thermal stability of the nanocomposites was not compromised due to the addition of the coupling agent and reinforced nanoparticles.

THE EFFECT OF ELECTROLYTE TEMPERATURE AND SEALING SOLUTION IN ANODIZING OPERATION ON HARDNESS AND WEAR BEHAVIOR OF 7075 -T6 ALUMINUM ALLOY

2019 ◽  
Vol 26 (02) ◽  
pp. 1850143
Author(s):  
SAEED NIYAZBAKHSH ◽  
KAMRAN AMINI ◽  
FARHAD GHARAVI
Keyword(s):  
Weight Loss ◽  
Wear Resistance ◽  
Aluminum Alloy ◽  
Wear Behavior ◽  
Anodic Oxide ◽  
Boiling Water ◽  
Electrolyte Temperature ◽  
Oxide Coatings ◽  
Sodium Dichromate ◽  
Pin On Disk

Anodic oxide coatings are applied on aluminum alloys in order to improve corrosion resistance and to increase hardness and wear resistance. In the current study, a hard anodic coating was applied on AA7075-T6 aluminum alloy. To survey the anodizing temperature (electrolyte temperature) effect, three temperatures, namely, [Formula: see text]C, 0∘C and 5∘C were chosen and the samples were sealed in boiling water and sodium dichromate to study the role of sealing. For measuring the oxide coatings porosity and hardness and also for comparing the samples’ wear resistance field-emission scanning electron microscopy (FESEM), microhardness test and pin-on-disk method were utilized, respectively. The results showed that by increasing the anodizing temperature, hardness and consequently wear resistance decreased so that hardness and weight loss in the samples with no sealing decreased from 460[Formula: see text]HV and 0.61[Formula: see text]mg at [Formula: see text]C to 405 and 358[Formula: see text]HV and 1.05 and 1.12[Formula: see text]mg at 0∘C and 5∘C, respectively, which is due to the porosity increment by increasing the anodizing temperature. Also, sealing in boiling water and dichromate contributed to soft phases and coating hydration, which resulted in a decrease in hardness and wear resistance. Hardness and weight loss in the coated samples at [Formula: see text]C decreased from 460[Formula: see text]HV and 0.61[Formula: see text]mg in the samples with no sealing to 435 and 417[Formula: see text]HV and 0.72 and 0.83[Formula: see text]mg in the samples sealed in boiling water and dichromate, respectively.

scholarly journals On the Microstructural, Mechanical and Tribological Properties of Mo-Se-C Coatings and Their Potential for Friction Reduction against Rubber

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1336
Author(s):  
Jorge Caessa ◽  
Todor Vuchkov ◽  
Talha Bin Yaqub ◽  
Albano Cavaleiro
Keyword(s):  
Carbon Content ◽  
Friction And Wear ◽  
Current Mode ◽  
Friction Reduction ◽  
Transition Metal Dichalcogenide ◽  
Butadiene Rubber ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction ◽  
Pin On Disk

Friction and wear contribute to high energetic losses that reduce the efficiency of mechanical systems. However, carbon alloyed transition metal dichalcogenide (TMD-C) coatings possess low friction coefficients in diverse environments and can self-adapt to various sliding conditions. Hence, in this investigation, a semi-industrial magnetron sputtering device, operated in direct current mode (DC), is utilized to deposit several molybdenum-selenium-carbon (Mo-Se-C) coatings with a carbon content up to 60 atomic % (at. %). Then, the carbon content influence on the final properties of the films is analysed using several structural, mechanical and tribological characterization techniques. With an increasing carbon content in the Mo-Se-C films, lower Se/Mo ratio, porosity and roughness appeared, while the hardness and compactness increased. Pin-on-disk (POD) experiments performed in humid air disclosed that the Mo-Se-C vs. nitrile butadiene rubber (NBR) friction is higher than Mo-Se-C vs. steel friction, and the coefficient of friction (CoF) is higher at 25 °C than at 200 °C, for both steel and NBR countersurfaces. In terms of wear, the Mo-Se-C coatings with 51 at. % C showed the lowest specific wear rates of all carbon content films when sliding against steel. The study shows the potential of TMD-based coatings for friction and wear reduction sliding against rubber.

scholarly journals Net-Shape NiTi Shape Memory Alloy by Spark Plasma Sintering Method

2021 ◽  
Vol 11 (4) ◽  
pp. 1802
Author(s):  
Sneha Samal ◽  
Orsolya Molnárová ◽  
Filip Průša ◽  
Jaromír Kopeček ◽  
Luděk Heller ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Spark Plasma Sintering ◽  
Memory Effect ◽  
Niti Alloy ◽  
Niti Shape Memory Alloy ◽  
Good Shape ◽  
Plasma Sintering ◽  
Shape Memory Effects ◽  
Spark Plasma

An analysis of the shape memory effect of a NiTi alloy by using the spark plasma sintering approach has been carried out. Spark plasma sintering of Ti50Ni50 powder (20–63 µm) at a temperature of 900 °C produced specimens showing good shape memory effects. However, the sample showed 2.5% porosity due to a load of 48 MPa. Furthermore, an apparent shape memory effect was recorded and the specimens were characterized by uniformity in chemical composition and shape memory alloys of NiTi showed significant austenite phases with a bending strain recovery of >2.5%.

Sliding Wear Behavior of Remelted Al2O3-TiO2 Plasma Sprayed Coatings on Titanium

2016 ◽  
Vol 254 ◽  
pp. 231-236 ◽  
Author(s):  
Ion Dragoş Uţu ◽  
Gabriela Marginean ◽  
Iosif Hulka ◽  
Viorel Aurel Şerban
Keyword(s):  
Sliding Wear ◽  
Wear Behavior ◽  
Pure Titanium ◽  
Titanium Substrate ◽  
Atmospheric Plasma ◽  
Wear Properties ◽  
Before And After ◽  
Sprayed Coating ◽  
Pin On Disk ◽  
Sprayed Coatings

Microstructure and wear properties of the Al2O3-13.wt% TiO2 thermally sprayed coatings before and after remelting were investigated in this study. The coatings were deposited on a pure titanium substrate using the atmospheric plasma spraying (APS) process. The as-sprayed coatings were electron beam (EB) modified in order to improve their compactness and bonding strength.The effect of EB remelting on the microstructure, phase constituents and wear properties was investigated using scanning electron microscopy (SEM), X-Ray diffraction technique and hardness measurements. The sliding wear behavior was tested using a pin on disk method.The results showed that the remelting process had a positive effect removing the lamellar defect of the as-sprayed coating and improving the compactness, hardness and wear behavior.

scholarly journals Investigation on Microblasting Applied to CrN Coatings

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Lorenzo Montesano ◽  
Annalisa Pola ◽  
Marcello Gelfi ◽  
Giovina Marina La Vecchia
Keyword(s):  
Wear Behavior ◽  
Corrosion And Wear ◽  
Crn Coating ◽  
Evaporation Technique ◽  
Cathodic Arc Evaporation ◽  
Quenched And Tempered Steel ◽  
Pin On Disk ◽  
Arc Evaporation ◽  
Cathodic Arc ◽  
Crn Coatings

A microblasting treatment carried out on CrN coated samples was studied to investigate the induced effect on corrosion and wear resistance. CrN coating was deposited through Cathodic Arc Evaporation technique on quenched and tempered steel. The properties of the coating were studied by hardness measurements, scratch, potentiodynamic, and pin-on-disk tests. The results show that microblasting reduces the corrosion resistance while improving the wear behavior.

Investigation of wear on the upper edges of webs of thin-film coated single-screw extruders processing pure polymers

2021 ◽  
Vol 63 (2) ◽  
pp. 143-150
Author(s):  
Torben Buttler ◽  
Jens Hamje ◽  
Rolf Reiter ◽  
Volker Wesling
Keyword(s):  
Wear Behavior ◽  
Cold Work ◽  
Polymer Processing ◽  
Chromium Nitride ◽  
Metallographic Examination ◽  
Test Speed ◽  
Single Screw Extruders ◽  
Pin On Disk ◽  
Screw Extruders ◽  
Disk Test

Abstract During polymer extrusion there are a variety of situations in which the screwthread of the extrusion screw has an unlubricated metal-to-metal contact with the barrel wall. At the same time the screw coating is subjected to the highest loads. The combination of a secondary hardening cold work steel 1.2379 and a chromium nitride coating deposited by ARC-PVD, which is frequently used in polymer processing, is characterized and investigated. The characterization is done by metallographic examination, SEM and CLSM. The tests were performed on a pin-on-disk and a pin-roll test rig. Different roughness levels were tested on the pin-on-disk test, where massive differences in wear behavior were found. A hybrid surface structure is proposed to optimize the tribosystem. On the pin-on-disk test stand, rollers made of the same material pairing were tested. The test speed was varied to highlight differences and similarities between the tribological systems. A wear minimization of 50 % was achieved and the similarities between the tribological systems were highlighted. In addition, the investigations led to the development of a new model thesis which provides a reason for the development of stippling on the screw when processing polycarbonate.

Influence of the particle size on the physical, mechanical and tribological properties of composites for brake pads

2021 ◽  
pp. 36-40
Author(s):  
F.F. Yusubov
Keyword(s):  
Particle Size ◽  
Composite Materials ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Phenol Formaldehyde ◽  
Environmentally Friendly ◽  
Brake Pads ◽  
Mechanical And Tribological Properties ◽  
Pin On Disk ◽  
Properties Of Composites

Tribotechnical indicators of environmentally friendly frictional composite materials with phenol-formaldehyde matrix are studied. Friction tests were carried out on a MMW-1 vertical tribometer according to the pin-on-disk scheme. Keywords: brake pads, composites, friction and wear, plasticizers, degradation, porosity. [email protected]

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