Tribological Wear Tests Research Articles

Mechanical characterization of tin coatings with biomedical application in elbow prostheses

The present work aims to study TiN films deposited on AISI 316L stainless steel substrates by physical vapor deposition through the Magnetron Sputtering technique with CD, heating it at a temperature of 200º and a constant time of 30 min. Identifying the mechanical properties to be used in biomedical applications, the microstructural characterization was performed by Optical Microscopy (OM) and Scanning Electron Microscopy (SEM). Adhesion tests were performed under the VDI 3198 standard. Tribological wear tests were performed using a 6 mm chromium plated steel pin (AISI 52100) on coated and uncoated substrates to study and compare the sliding effect continuing the same circumferential geometry, with a stroke length of 200 m and a load of 5N in wet and dry way using milli-Q water to simulate biological fluids in order to test the performance and durability of the implant.

Investigating the microstructures and properties of Mg‐Al LDH film‐coated Mg‐Li alloy: Effect of hydrothermal temperature

AbstractMagnesia‐alumina layered double hydroxide (Mg‐Al LDH) films grown in situ on LA43M magnesium‐lithium (Mg‐Li) alloy were synthesized utilizing the hydrothermal method. Scanning electron microscopy (SEM), energy‐dispersive spectrometry (EDS), and X‐ray diffraction (XRD) were used to characterize the surface morphologies, composition, and phase of the Mg‐Al films. The corrosion resistance of the Mg‐Al films was estimated via immersion experiment and hydrogen evolution test, and the tribological properties were investigated using tribological wear tests. The results showed that the thickness of the Mg‐Al LDH film enhanced, and the size of the LDH sheets increased as the hydrothermal temperature raised, resulting in the improvement of the corrosion and wear resistance. When the hydrothermal temperature reached 110°C, interlayer anions were loaded the most, and the film achieved the optimal thickness. The Mg‐Al LDH film had the optimum corrosion resistance and tribological properties. At this point, the weight loss of the film was 1.3560 mg·cm–2, and the average friction coefficient was .149. It demonstrated that synthesizing Mg‐Al LDH at a hydrothermal temperature of 110°C was an effective approach to improve the corrosion resistance of LA43M.

Tribological Properties of Coating Obtained by Magnetron Sputtering of the Composite Target Ni-Cr-B<sub>4</sub>C

The paper studies the tribological behavior of a Ni-B/Cr7C3 nanocomposite coating applied by magnetron sputtering on a Ni-Cr-B4C composite target. The composite target was obtained by detonation gas-thermal spraying of Ni-Cr-B4C powder composition. The study determined the hardness of the coating amounting to 7.8 GPa. The distribution of chemical elements in the contact zone of ball-coating friction by energy dispersive spectroscopy (EDS) was studied. The wear track width was 324 μm. Tribological wear tests and determination of adhesion/cohesion strength showed that Ni-B/Cr7C3 coatings have good wear resistance, and abrasive and adhesion wear mechanisms act simultaneously during wear. The resulting coatings can be used to protect critical parts and mechanisms susceptible to abrasive and adhesive wear.

Influence of Sandblasting Process on Tribological Properties of Titanium Grade 4 in Artificial Saliva for Dentistry Applications.

Titanium Grade 4 (Ti G4) is widely used in medicine for dental implants. The failure-free life of implants depends on their properties such as resistance to wear and friction processes. This paper presents an analysis of the influence of sandblasting on tribological wear of commercial dental implants made of TiG4 in artificial saliva. Tribological wear measurements were performed in a reciprocating motion in the ball-on-disc system. The scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) method was used to characterize the surface of the implants before and after the tribological wear test. The microhardness of Ti G4 was measured before and after sandblasting by the Vickers method. The contact angle was determined by the method of sitting drop in air. The residual stress test using the X-Ray Diffraction (XRD) single-{hkl} sin2ψ method was carried out. The compressive residual stress of 324(7) MPa and surface hardening of Ti G4 was revealed after sandblasting with Al2O3 particles of 53–75 μm in diameter. It was found that sandblasting changes the surface wettability of Ti G4. The intermediate wettability of the mechanically polished surface and the hydrophobicity of the sandblasted surface was revealed. Sandblasting reduces the tribological wear and friction coefficient of Ti G4 surface in saliva. The three-body abrasion wear mechanism was proposed to explain the tribological wear of Ti G4 in saliva.

Assessment of Wear Properties under Dry Sliding Conditions on AISI 301LN Austenitic Stainless Steel by Plasma Nitriding Process

In industry, mechanical components must operate under conditions conditions such as variable load, speed, temperature and various chemical environments. Materials are selected depending on their application. They are selected for commercial availability, cost and properties such as strength, hardness etc. Many engineering errors are due to fatigue, corrosion and poor wear resistance occurring on its surface. This causes cracks in the surface that shortens the service life of the material. Also, the surfaces of materials are exposed to strong thermal, chemical and shock loads. Chosen for this research work, AISI 301LN materials have low surface hardness and poor wear properties, which can limit their applications were components mate each other. AISI 301LN stainless steel was treated with plasma nitriding at a low temperature of about 650°C. It was observed that a mixture of ferrites and gradually nitrogenous matter accumulates in the following layers namely iron nitride. Further nitriding was carried out to 20 hrs, 40 hrs, 60 hrs and the specimen were named as PL1, PL2 and PL3 respectively. It was observed that Cr-N layer were formed on the outer surface. Wear tests were carried out on a tribological wear test machine to study the wear behavior. A comparison is made between treated and untreated specimens. The microstructures are investigated with scanning electron microscope.

Utilization of the focus variation method for determining the wear volume in the pin-on-disk sliding test

Abstract The measurement of wear volume in tribological tests is a critical step in wear characterization. There are many methods and instruments for wear volume measurement reported in the literature and most of them have already been commercialized. These commonly determine wear volume by means of tactile or optical methods, requiring costly and/or specifically developed instruments. In this study, an alternative method for determining wear volume, obtained after a sliding test with a pin-on-disk type apparatus, using focus variation microscopy is reported. A reflective-type light microscope, equipped with a digital camera, together with a range of computer software was used for the line profiling of wear scars, rather than a specialized focus variation microscope. In this study the relatively “shallow” depth of field at the high magnification of the light microscope was precisely used for determining surface line profiles on both slightly and heavily worn specimen surfaces after a series of tribological wear tests. Results of the study method were compared with both profilometric measurements obtained from a 3D optical microscope and with those obtained using a previously reported method. This comparison showed that the method under development and tested in this study yielded successful measurements, comparable to those obtained using the much more expensive 3D optical microscope.

A Review on Tribological Wear Test Rigs for Various Applications

To mimic a tribosystem setup to the real-time model while taking into consideration the subject of green tribology, many tribological wear test rigs are invented. The current work is a dedicated review on the latest development of various tribological wear test rigs build for numerous applications. With the aid of diagrams, the working principles of the machines which are built on specific standards are discussed. Their operating parameters associated with related research using these machines are also included. In addition to that, recommendations and directions for improvements in tribology machines are reported.

Tribological properties evaluation of Ni-P coating manufactured with electroless plating on aluminum alloy substrate

Results of tribological tests of Ni-P coating were presented in following paper. Tests were conducted with tribotester device using linear reciprocating wear test. Tribological wear test conditions, especially speed, load and sample geometry were described. Characteristics of coefficient of friction variation during wear testes were recorded. Conclusions included results interpretation especially focusing on influence of coating thickness in its properties.

Molecular Characterization of Lubricant Degradation Produced in a Tribological Wear Test Using TOF-SIMS Imaging MS

Molecular Characterization of Lubricant Degradation Produced in a Tribological Wear Test Using TOF-SIMS Imaging MS

Tribology and high temperature friction wear behavior of MCrAlY laser cladding coatings on stainless steel

Temperature can have a significant effect on the extent of wear damage of metallic components. Thermal barrier coatings can improve the high temperature tribological and friction wear behavior. In this work the dry friction and wear behavior at low and high temperature of NiCoCrAlY and CoNiCrAlY laser cladding coatings were evaluated, as well as for the austenitic stainless steel AISI 304 used as substrate. Dense coatings, with good bonding to the substrate was obtained by coaxial laser cladding tracks (40% overlapping), with previously optimized laser parameters. Tribological wear tests were performed by sliding wear at room temperature and 500°C, with an Al2O3 ball on disk configuration tribometer. The wear scar surface was evaluated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) microanalysis. The 3D topography of the wear track was determined by inductive contact profilometer which enabled the wear rate calculation. The microstructure of the coatings consists of γNi/β-NiAl or γCo/β-(Co,Ni)Al phases depending on the chemical composition of the alloy, as confirmed by X-ray diffraction (XRD) analysis. The wear test results show a reduction in wear rate at high temperature for all materials tested. For the NiCoCrAlY coating, the high temperature also reduces the friction coefficient, while it significantly increases the friction coefficient of CoNiCrAlY coating. The main damage mode is abrasion and adhesion, caused by the oxide and partially-oxidized particles in the contact surface. The coatings and substrate results were compared, resulting in an improved wear behavior.

Vacuum vapor deposition of PFPE molecules on CHxNy and CHxFy amorphous carbon surfaces

According to the demand of increasing storage density for the magnetic data storage, a contact recording system is proposed, in which the head constantly makes contact with the disk surface during read/write cycles. In this system a stronger lubricant film for head disk interface (HDI) is required. In a conventional dip-coating method, which is carried out under atmospheric conditions, however, a fresh diamond like carbon (DLC) surface adsorbs several contaminations from the air and a strong lubricant layer is difficult to form on the DLC surface. In this study, a DLC layer is coated on a Si substrate by a plasma chemical vapor deposition (PCVD) method, then the DLC-coated Si sample is transferred to another vacuum chamber without being exposed to the atmosphere, and a perfluoropolyether (PFPE) lubricant film is vapor-deposited on the sample. The sample is analyzed by XPS and compared to the surface on which the PFPE lubricant is dip-coated. It is noted that both samples are rinsed after the coatings and the loose PFPE molecules are washed away. A thicker bonded layer of PFPE is formed on the DLC surface treated by vapor deposition. A tribological wear test is also carried out using a pin-on-disk tribotester. Both results show that the tribological characteristics are improved by the vapor deposition of PFPE molecules compared to the dip-coating method.

N+ ion implantation of Ti6Al4V alloy and UHMWPE for total joint replacement application.

Multidirectional pin-on-plate tribological wear tests were performed to evaluate and compare the tribological behavior of N+ ion-implanted and unmodified Ti6Al4V/ultra high molecular weight polyethylene (UHMWPE) sliding couples, for total joint replacement (TJR) applications. Knoop microhardness indentations were measured and an increase in surface hardness of more than twofold and up to four times, respectively, was observed for the Ti6Al4V alloy and UHMWPE after N+ ion implantation, at a load of 1 gf. Increase in hardness was attributed to the formation of TiN precipitates and cross-linking in the alloy and polymer, respectively. Wear test results showed that N+ ion implantation reduced surface wear of the Ti6Al4V alloy and, in turn, significantly reduced the wear of the mating UHMWPE. Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), non-contacting interferometry and optical microscopy were used to characterize both modified and unmodified material surfaces prior to and after tribological wear tests. The results indicated that N+ ion-implanted Ti6Al4V/UHMWPE sliding couples were distinctly superior to the unmodified sliding couples, and demonstrated a definite potential for the use of N+ ion-implanted Ti6Al4V and implanted UHMWPE as load bearing surfaces in TJR prostheses. (Journal of Applied Biomaterials & Biomechanics 2003; 1:164-71).

Tribological study of joint pathology.

Osteoarthritis (OA) is the most common among the numerous forms of arthritides, affecting millions of people worldwide. Low-grade synovitis is an inflammatory condition commonly seen in OA. In joint fluids aspirated from patients with low-grade synovitis, increased numbers of white blood cells have been detected. During periods of prolonged inflammation, these cells may lyse, releasing lysate into the synovial fluid. The effect of this lysate on cartilage wear and damage has not been investigated previously. A lysate of bovine white blood cells was added to normal bovine synovial fluid. Both lysate treated and normal synovial fluids were used in in vitro tribological wear tests to determine the effect of the white blood cell lysate on the wear and damage of articular cartilage. Cartilage wear increased by a factor of 2.6 when normal synovial fluid was treated with white blood cell lysate. Histology showed considerable damage and fibrillation of the lysate-treated cases, in addition to a loss of proteoglycans in the deep layer of the cartilage. The untreated control cases showed no significant damage or histological abnormalities. It is suspected that the wear and damage seen in the lysate-treated cases is partially due to enzymatic activity within the cartilage. The results of this study suggest that the products of joint inflammation, or synovitis, may have an adverse effect on cartilage wear and damage.

Optimization of PVD Parameters for the Deposition of Ultrahard Ti–Si–B–N Coatings

Multicomponent Ti–Si–B–N coatings were deposited on high-speed steel (HSS) substrates by reactive magnetron sputtering using a SHS TiB + 20 wt% Si target. The influences of the substrate temperature, bias voltage, and nitrogen partial pressure on the structure and the elemental compositions of the films were studied. The films were characterized by high-resolution transmission electron microscopy (HRTEM), Auger spectroscopy (AES), and X-ray diffraction (XRD). The results of HRTEM analysis indicated the formation of an ordered–disordered structure with fine crystalline grains of hexagonal Ti(B,N)x phase and amorphous integrain layers. The stoichiometry of the Ti(B,N)x phase was strongly affected by PVD process parameters. The films were characterized in terms of their microhardness and wear resistance. The reasons for the high value of microhardness appear to be the result of stoichiometric phase composition, compressive residual stress, and dense and fine microstructure of the Ti–Si–B–N coatings. The tribological wear test results indicated the superior wear-resistant properties of Ti–Si–B–N coatings compared to TiN and Ti(C,N) coatings.