scholarly journals The Effect of Laser Nitriding on Surface Characteristics and Wear Resistance of NiTi Alloy with Low Power Fiber Laser

2021 ◽  
Vol 11 (2) ◽  
pp. 515
Author(s):  
Hao Wang ◽  
Ralf Nett ◽  
Evgeny L. Gurevich ◽  
Andreas Ostendorf
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Low Power ◽  
Fiber Laser ◽  
Niti Alloy ◽  
Nitride Layer ◽  
Wear Testing ◽  
Wear Loss ◽  
Laser Nitriding

The laser nitriding was performed in nitrogen gas at room temperature (20 °C) and low temperature (−190 °C) by a low power fiber laser to modify the wear and abrasion resistance of NiTi alloy. The surface roughness and element composition were analyzed by roughness device and energy-dispersive X-ray spectroscopy respectively. The results of roughness show that laser treatment can change the surface roughness due to the laser remelting. The effect of laser nitriding on the microhardness, friction coefficient, and worn scars of NiTi alloy was also studied, which shows that the microhardness of the NiTi alloy increases after laser nitriding. The optical microscope and scanning electron microscope were used to characterize the surface of NiTi alloy after wear testing to observe the microstructure of worn scars. The results show that the laser nitriding with different parameters can induce a nitride layer with different thicknesses and the higher energy deposition is the key factor for the formation of the nitride layer, which can decrease the friction coefficient and reduce wear loss during the application of NiTi alloy. The improvement of wear resistance can be attributed to the hard nitriding layer.

Wear Testing of Principal Friction Pairs in Axial Piston Pump Based on Taguchi Design Method

2015 ◽  
Vol 779 ◽  
pp. 26-34 ◽  
Author(s):  
Cun Ran Zhao ◽  
Ji Hai Jiang ◽  
Chong Ke
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Design Method ◽  
Friction Pair ◽  
Piston Pump ◽  
Wear Testing ◽  
Wear Loss ◽  
Axial Piston Pump ◽  
Axial Piston ◽  
Selection Of

While axial piston pump is the core component of hydraulic system, its service life and reliability depend much on the selection of materials, friction pairs and process parameters. To identify these factors, wear condition of friction pair is conducted by using MWF-10 wear rig. Based on ANOVA of Taguchi Method,the influences of surface roughness and hardness on wear loss and friction coefficient are compared. In addition, the results show that the optimal friction pair and surface roughness of hard specimens have influence mostly on the wear loss and the friction coefficient.

scholarly journals Experimental Investigation on the Wear and Damage Characteristics of Machined Wheel/Rail Materials under Dry Rolling-Sliding Condition

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 472
Author(s):  
Peijie Liu ◽  
Yanming Quan ◽  
Junjie Wan ◽  
Lang Yu
Keyword(s):  
Surface Roughness ◽  
Plastic Deformation ◽  
Surface Defects ◽  
Wear Behavior ◽  
Friction Pair ◽  
Surface Hardness ◽  
Wear Testing ◽  
Wear Loss ◽  
Machining Parameters ◽  
Deformation Layer

To guarantee the smooth operation of trains, rail grinding and wheel turning are necessary practices to remove surface defects. Surface integrity of machined wheel/rail materials is significant to affect their tribological performance. In this paper, firstly, the wheel specimens were turned by a CNC lathe and the rail specimens were ground by a cylindrical grinding machine with various machining parameters. Then, the wear and damage behavior of the machined wheel/rail discs was systematically investigated via a twin-disc wear testing apparatus under dry rolling-sliding condition. The experimental results show that the surface hardness of rail discs after machining is slightly higher than that of wheel discs, while the surface roughness and plastic deformation layer of wheel discs are much larger than those of rail discs. The surface hardness increase degree of rail discs and their thickness of plastic deformation layer are greater than those of wheel discs after the rolling-sliding test. The wear loss of wheel discs is much larger than that of rail discs. Surface roughness, hardness and plastic deformation layer of wheel/rail discs after machining exert a comprehensive effect on the wear behavior, and friction pair with appropriate original surface hardness and roughness generates the smallest amount of wear loss.

scholarly journals Abrasive Wear Resistance of Plasma-Nitrided Ti Enhanced by Ultrasonic Surface Rolling Processing Pre-Treatment

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3260
Author(s):  
Dingshun She ◽  
Shihao Liu ◽  
Jiajie Kang ◽  
Wen Yue ◽  
Lina Zhu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Abrasive Wear ◽  
Wear Debris ◽  
Plasma Nitriding ◽  
Lunar Regolith ◽  
Nitride Layer ◽  
Abrasive Wear Resistance ◽  
Pre Treatment ◽  
Worn Surface

The objective of the given work was to investigate abrasive wear behaviours of titanium (Ti) treated by ultrasonic surface rolling processing (USRP) pre-treatment and plasma nitriding (PN). Simulated lunar regolith particles (SLRPs) were employed as abrasive materials during characterization of tribological performances. The experimental results showed that SLRPs cause severe abrasive wear on Ti plasma-nitrided at 750 °C via the mechanism of micro-cutting. Due to the formation of a harder and thicker nitriding layer, the abrasive wear resistance of the Ti plasma-nitrided at 850 °C was enhanced, and its wear mechanism was mainly fatigue. USRP pre-treatment was effective at enhancing the abrasive wear resistance of plasma-nitrided Ti, due to the enhancement of the hardness and thickness of the nitride layer. Nevertheless, SLRPs significantly decreased the friction coefficient of Ti treated by USRP pre-treatment and PN, because the rolling of small granular abrasives impeded the adhesion of the worn surface. Furthermore, USRP pre-treatment also caused the formation of a dimpled surface with a large number of micropores which can hold wear debris during tribo-tests, and finally, polishing and rolling the wear debris resulted in a low friction coefficient (about 0.5).

scholarly journals Tribological Properties of Polymer Composite with Impregnated Quasicrystal Nanoparticles

2021 ◽  
Vol 15 ◽  
pp. 189-195
Author(s):  
Y. A. Utkin ◽  
A. A. Orekhov ◽  
Thant Zin Hein
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Polymeric Materials ◽  
Degree Of Crystallinity ◽  
Thermoplastic Polymer ◽  
Noticeable Effect ◽  
Instrument Making ◽  
The Degree Of Crystallinity

In this work, a study is carried out on the introduction of quasicrystal particles into a thermoplastic polymer and it is shown that this leads to changes in the structure of polyethylene. The introduction of quasicrystal particles into a thermoplastic polymer leads to changes in the structure of polyethylene: the degree of crystallinity decreases from 42% (PE) to 27% (10AlCuFe/PE) with increasing concentration of the filler, the ratio of bands corresponding to amorphous and crystalline regions in the IR spectra changes, which indicates on the amorphization of the PE structure. The specimens have improved wear resistance (the wear rate decreased by 96% compared to the original PE), but the friction coefficient remained practically unchanged. It is shown that the addition of quasicrystal nanoparticles in a small amount (up to 10 wt.%) leads to an increase in hardness, but does not have a noticeable effect on the surface roughness. The results obtained indicate that quasicrystals can serve as effective fillers for promising polymeric materials in products for aerospace, instrument making, and other industries.

Wear of Spiral Seal Cone Bit in Complex Formations

SPE Journal ◽  
2021 ◽  
pp. 1-16
Author(s):  
Y. Zhou ◽  
J. H. Hu ◽  
B. Tan ◽  
Y. Jiang ◽  
Y. F. Tang
Keyword(s):  
Friction Coefficient ◽  
Working Conditions ◽  
Wear Mechanism ◽  
Testing Machine ◽  
Wear Test ◽  
Simulation Method ◽  
Wear Testing ◽  
Wear Loss ◽  
Wear Depth ◽  
Wear Properties

Summary Sealing is a technical bottleneck that affects drilling efficiency and cost in deep, difficult-to-drill formations. The spiral combination seal with active sand removal performance is a new type of seal, and the wear mechanism is not clear, resulting in no effective design. In this study, the wear properties of materials were measured by a friction-and-wear testing machine, and the measurement methods and criteria of wear loss and friction coefficient were established. The fitting function of working condition and friction coefficient was studied by fitting regression method. The law of influence of working conditions on friction coefficient and wear amount was determined. The actual wear model and evaluation criteria of wear condition were established by using wear test data and geometric relationship. The relationship among working conditions, contact stress, and wear depth is determined by numerical simulation method, and the wear mechanism of the new seal is revealed, which provides a theoretical basis for its application.

Wear properties of WC–Co and WC–CoCr coatings applied by HVOF technique on different steel substrates

2020 ◽  
Vol 62 (12) ◽  
pp. 1235-1242
Author(s):  
Hatice Varol Ozkavak ◽  
Serife Sahin ◽  
Mehmet Fahri Sarac ◽  
Zehra Alkan
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Steel Substrate ◽  
Wear Properties ◽  
Sem Images ◽  
Steel Alloys ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Aisi 4340

Abstract Low alloy and stainless steel are the most used types of iron-based materials world wide. Their use against in machine element work, reclamation, corrosion and wear resistance are still challenging. To overcome this problem, many steel alloys are coated with cermet coatings to protect the parts from wear and corrosion. In the present study, WC-Co and WC-CoCr coatings were applied by means of a high velocity oxy-fuel (HVOF) technique on AISI 304, AISI 1040, and AISI 4340 steel alloys used as substrates. The aim was to investigate surface properties and wear resistance of the coatings and to determine their relationship with the type of coating and substrate. In accordance with this purpose, hardness and thickness of the coatings were measured, sliding wear tests were performed, scanning electron microscope (SEM) images and X-ray diffractions (XRD) were taken, surface roughness and friction coefficients were determined. The results showed that the WC-CoCr coatings had higher hardness and lower thickness than the WC-Co coatings. Maximum hardness was obtained in the WC-CoCr coating applied to AISI 4340 steel, which was also the hardest alloy among those studied. After wear resistance tests, it was revealed that the wear resistance of the WC-CoCr coatings was better than that of the WC-Co coatings for each steel substrate. During the coating, the new phases resulting from the decomposition of the WC phase in the WC-CoCr coatings contributed more to wear resistance than those of the WC-Co coatings. A lower friction coefficient and lower surface roughness of the WC-CoCr coatings during wear were obtained, resulting in higher wear resistance. A WC-CoCr coating on AISI 4340 alloy which has the highest hardness, lowest surface roughness and lowest friction coefficient resulted in the highest wear resistance among all types studied.

scholarly journals Tribological Properties of PVD Ti/C-N Nanocoatnigs

2017 ◽  
Vol 54 (2) ◽  
pp. 64-71
Author(s):  
A. Leitans ◽  
J. Lungevics ◽  
J. Rudzitis ◽  
A. Filipovs
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Roughness Parameter ◽  
Surface Wear ◽  
Roughness Parameters ◽  
Coating Deposition ◽  
2D And 3D

Abstract The present paper discusses and analyses tribological properties of various coatings that increase surface wear resistance. Four Ti/C-N nanocoatings with different coating deposition settings are analysed. Tribological and metrological tests on the samples are performed: 2D and 3D parameters of the surface roughness are measured with modern profilometer, and friction coefficient is measured with CSM Instruments equipment. Roughness parameters Ra, Sa, Sz, Str, Sds, Vmp, Vmc and friction coefficient at 6N load are determined during the experiment. The examined samples have many pores, which is the main reason for relatively large values of roughness parameter. A slight wear is identified in all four samples as well; its friction coefficient values range from 0,.21 to 0.29. Wear rate values are not calculated for the investigated coatings, as no expressed tribotracks are detected on the coating surface.

Research on the Friction and Wear Properties of the NBR under Dry Sliding and Water Lubrication

2013 ◽  
Vol 420 ◽  
pp. 234-239
Author(s):  
Feng Yan Yang ◽  
Shi Jie Wang ◽  
Xiao Ren Lv
Keyword(s):  
Friction Coefficient ◽  
Abrasive Wear ◽  
Coefficient Of Friction ◽  
Testing Machine ◽  
Water Lubrication ◽  
Wear Testing ◽  
Wear Loss ◽  
Dry Sliding ◽  
Wear Properties ◽  
Lubrication Performance

The wear mechanisms of different graphite contents of NBR by 45# steel under dry sliding and water lubrication were investigated. On MPV-600 computer-controlled abrasive wear testing machine, the coefficients of friction were measured continuously. Results showed that under dry sliding condition, the rubber wear loss is big, the coefficient of friction is higher, the temperature of the friction surface is rise obviously. Wear loss and friction coefficient of NBR decrease with the increase of graphite contents; With the increase of graphite contents wear loss and the friction coefficient decreases, and is mainly due to the graphite lubrication performance and increase the stiffness of the rubber contact area. At low content of graphite, adhesive wear of NBR is showed, in the high content of graphite, abrasive wear is showed. Water lubrication condition, wear surface level off, the wear loss is very small, and the lubrication and cooling effect of water makes the friction coefficient decrease. Graphite content is higher, the wear loss and coefficient of friction is smaller.

Coating of Fe-Mn-Si Shape Memory Materials on AISI 304 Stainless Steel by Laser Cladding Method

2013 ◽  
Vol 477-478 ◽  
pp. 1393-1396
Author(s):  
Peng Xu ◽  
Heng Ju ◽  
Cheng Xin Lin ◽  
Chao Yu Zhou
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Shape Memory ◽  
Laser Cladding ◽  
304 Stainless Steel ◽  
Wear Loss ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Shape Memory Materials

Using laser cladding method, the coating of Fe-Mn-Si shape memory materials (SMM) was prepared on the surface of AISI 304 stainless steel. The microstructure and microhardness of SMM laser cladding coating were measured by using a metallographic microscope and a scanning electron microscope, respectively. The phase composition was determined by X-ray diffraction. The wear resistance was evaluated on a high speed reciprocating friction tester. The results show that microhardness of the SMM coating is about Hv263, higher than that of the substrate (Hv225); the SMM coating is composed of ε-martensite and γ-austenite phases; the average friction coefficient of the substrate and SMM coating is about 0.85 and 0.71; the SMM laser cladding coating is of excellent wear resistance validated by friction coefficient, worn-out appearance and wear loss.

scholarly journals Effect of SiO2 and Al2O3 nanoparticles on wear resistance of PMMA acrylic denture teeth

2020 ◽  
Vol 23 (3) ◽  
Author(s):  
Mohamed A Helal ◽  
Bin Yang ◽  
Esam Saad ◽  
Mohamed Abas ◽  
Mohamed Reda Al-kholy ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Weight Loss ◽  
Wear Resistance ◽  
Testing Machine ◽  
Sio2 Nanoparticles ◽  
Wear Testing ◽  
Al2o3 Nanoparticles ◽  
Nano Sio2 ◽  
Resistance Surface ◽  
Denture Teeth

Objective: This study aimed to evaluate the wear resistance of acrylic denture teeth containing silicon dioxide (nano-SiO2) and aluminum dioxide (nano-Al2O3) nanoparticles. Material and Methods: Poly methyl methacrylate (PMMA) denture tooth material was used to denture tooth material was used to fabricate 84 specimens (n=10) containing nano-SiO2 and nano-Al2O3 in concentrations 0.1wt%, 0.3wt%, and 0.5wt% of acrylic powder. A two-body wear testing machine and digital microscope were used to measure the changes in weight loss and surface roughness respectively. One-way ANOVA and pair-wise Tukey’s post-hoc tests were used for data analysis (α = 0.05). Results: Nano-SiO2 modified teeth material demonstrated a significant increase in weight loss in comparison conventional artificial acrylic teeth material (p ˂ 0.05) while nano- Al2O3 modified teeth material demonstrated non-significant increase in weight loss except for 0.5% subgroup (p ˂ 0.05). There is no significant differences regarding roughness change after wear simulation among all tested groups (p > 0.05). Conclusion: Nano-Al2O3 nanoparticles exhibit less negative effect than nano-SiO2 so; it could be used with caution if necessary.KeywordsAcrylic denture teeth; Al2O3 nanoparticles; SiO2 nanoparticles; wear resistance; surface roughness.

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