Friction Properties Research Articles

Experimental Study on Tribological, Rheological and Bio-degradability Characteristics of Canola Oil with TiO2 Nanoparticles as Bio-nanolubricants

In response to growing environmental concerns about the adverse effects of conventional lubricants, there has been a surge in the demand for eco-friendly alternatives. Biodegradable lubricants, crafted from renewable sources, represent a sustainable solution to address these environmental apprehensions. This research describes the tribological, rheological properties and biodegradability of rapeseed oil with 0.25 to 1.25 weight percent TiO2 nanoparticles as additives. The lubricant samples were prepared using a magnetic stirrer and an ultrasonic device. Friction and wear properties such as coefficient of friction and wear scar diameter were determined using a four-ball tester. In comparison with SAE20W40, samples 1 (0.25 weight percentage of TiO2) and sample 2 (0.5 weight percentage of TiO2) shown remarkably improved tribological performance, with 73.32% and 66.76% decreases in coefficient of friction (COF), respectively. Shear stress, shear rate and dynamic viscosity are analyzed using a rheometer. The acquired results are juxtaposed with both pure canola oil and various mineral oils for comparison. The nano-lubricant synthesized in this study emerges as a viable alternative to SAE10, DXT3 (steering fluid), and SAE20W50 grade oils, demonstrating lower friction and a reduced wear scar diameter. Biodegradability tests were performed on all generated samples using the Biochemical Oxygen Demand (BOD) apparatus, and all samples exhibited a BOD to Chemical Oxygen Demand (COD) ratio better than 0.5, indicating biocompatibility. The findings of the research investigation indicate that the combination of canola oil with TiO2 blends holds significant promise as an alternative to conventional synthetic lubricant oils.

Mechanical and anti-icing performance of superhydrophobic aluminum conductor by anodized oxide technique

Abstract Anodized oxide technology is a traditional surface treatment method used in the material engineering field to enhance the friction, anti-icing, anti-corrosion, and insulation properties of Al-based samples. Considering the anti-icing and insulation performance, anodized oxide technology has great application prospects in overhead transmission lines. In this study, the preparation process of Aluminum (Al) flat plates and Aluminum Cable Steel-Reinforce (ACSR) was explored by using anodizing technology to obtain superhydrophobic properties. Moreover, as the significant performance in the application of transmission lines, the mechanical performance (tensile strength) of Al conductors was evaluated to study the impact of anodized oxidation technology. The results show that anodized oxide technology can improve the tensile strength of aluminum clad steel bars and aluminum-stranded wires in ACSRs. In addition, the hydrophobicity and anti-icing performance of anodized wires can demonstrate potential application prospects in the field of anti-icing.

Influence of titanium carbide particles on the characteristics of microarc oxidation layer on Ti6Al4V alloy

The Microarc Oxidation (MAO) layer on titanium alloy was mainly composed of TiO2, and there were some defects, such as holes and cracks, which made the performance of the MAO layer not ideal. To enhance the properties of the MAO layer, titanium carbide (TiC) particles were added to the electrolyte of a phosphate–silicate system as an additive. Consequently, the MAO layers containing the TiC phase on Ti6Al4V alloy were produced. The MAO process, composition, microstructure, and hardness of the MAO layer were comprehensively analyzed. Their frictional performance was assessed under reciprocating friction conditions without lubrication. The findings suggested that added TiC particles in the electrolyte played a significant role in creating the MAO layer, enhancing its thickness. The electrolyte without TiC particles produced an MAO layer primarily composed of TiO2 in two different mineral forms (rutile and anatase). Adding TiC particles resulted in the presence of TiC within the MAO layer, thereby facilitating the formation of a reinforced oxide layer. This addition also led to an improvement in the densification of the layer and a reduction in porosity. Notably, corrosion resistance testing indicated that incorporating 6 g l−1 TiC into the electrolyte resulted in superior performance compared with that obtained from the base electrolyte alone by achieving 1.4 times higher corrosion resistance. Moreover, a hardness value of 690 HV for the MAO layer was attained at a content level of 9 g l−1 TiC, demonstrating a significant 65% enhancement compared to the base oxide layer. This finding also demonstrated significantly enhanced friction property with a wear-volume reduction to 0.81 mm3. The findings on the relationship between the preparation of the MAO layer and its structure and properties can provide valuable guidance for designing and preparing the MAO layer.

Frictional Properties of Simulated Fault Gouges Subject to Normal Stress Oscillation and Implications for Induced Seismicity

AbstractUnder critical conditions where experimental fault slip exhibits self‐sustained oscillation, effects of normal stress oscillation (NSO) on fault strength and stability remain poorly understood, as do potential effects of NSO on natural and induced seismicity. In this study, we employed double direct‐shear testing to investigate the frictional behavior of a synthetic, slightly velocity‐weakening (SVW) fault gouge (characterized by self‐sustained oscillation under quasi‐static shear loading), when subjected to NSO at different amplitudes (5%–20% of 5 MPa) and frequencies (0.001–1 Hz). During the experiment, fault displacement and gouge layer thickness were measured. Transmitted ultrasonic waves were also employed to probe grain contact states within the gouge layer. Our results show that fault weakening and unstable slip can be triggered at NSO frequencies ranging from 0.03 to 0.1 Hz and amplitudes exceeding 5%. Interestingly, an amplified shear stress drop and weakening effect were observed when the NSO frequency fell in 0.05–0.1 Hz. Analysis of transmitted ultrasonic waves in tests on the SVW gouge revealed fault dilation, accompanied by unstable slip and weakening. By extending an existing microphysical model (the “Chen‐Niemeijer‐Spiers [CNS]” model), to account for elastic effects of NSO on gouge microstructure and grain contact state, the mechanical and wave data obtained in our experiments on the SVW gouge was reproduced, suggesting an approach for modeling fault instability under upper crustal (SVW) conditions where normal stress is perturbed by subsurface operations, such as periodic gas storage stimulation of reservoir formations.

Microstructure, hardness, and tribological properties of Ni-Co/ SiO2 nanocomposite coating produced through pulsed current electrodeposition

This study investigates the development of Ni-Co/SiO2 nanocomposite coatings on mild steel surface using pulsed-current electrodeposition method. The effects of incorporating SiO2 nanoparticle and varying its concentration on the coatings' microstructure, microhardness, wear resistance, and frictional properties were assessed using field-emission electron microscopy, X-ray diffraction, Vickers microhardness testing, and dry sliding wear tests. The results indicated that the coatings exhibited two-phases of Ni-Co solid solution (α) with a face-centered cubic (FCC) crystal structure and hexagonal Co, a refined crystallite size of approximately 31 nm for Ni-Co and about 25 nm for Ni-Co/SiO2, along with a colony-like morphology that did not show any preferred growth direction. The amount of Ni-Co solid solution increased with the addition of SiO2 nanoparticles. The composite coatings demonstrated enhanced microhardness of 581 HV, which is 52 % greater than that of the Ni-Co coating, as well as improved wear resistance and a reduced friction coefficient compared to the unreinforced alloy coating. However, higher SiO2 content adversely impacted the tribological properties due to nanoparticle agglomeration. Analysis of the worn surfaces revealed a transition from abrasive wear to oxidative wear with increasing applied force for the coatings.

Normal fault localization controls during syn- and post-orogenic extension affecting thin-skinned architecture

Balanced cross sections through thrustbelts affected by post-orogenic extension reveal that normal faults are mostly developed in the backlimbs of pre-existing, asymmetric, fault-propagation and detachment folds. Outcrop study, geological cross section balancing, reflection seismic interpretation and numerical modeling in the Eastern Balkans indicate that the nucleation of these normal faults is affected by the occurrence of plastic strain zones in backlimbs, represented by clusters of small-scale dilatant shear fractures. Thrustbelt segments where these zones did not evolve into thrust faults and became passively rotated into steeper geometries are prone to normal fault development during post-orogenic extension. Instead of developing its own precursor fracture clusters, each normal fault of this type nucleates using pre-existing clusters as a shortcut in its development. Rare occurrences of post-orogenic extension-driven faults, which reactivate entire pre-existing thrust fault ramps or develop in fold forelimbs indicate the existence of other parameters that co-control the development of normal faults in this setting. These parameters include thrustbelt topography as well as variations in décollement geometry and frictional properties.

Biomass-Derived Carbons as Friction Reducing Additives for Lubricants: Tribological Properties of Biochars and Activated Carbons Obtained from Sugar Cane Bagasse

Activated carbons are commonly used for adsorption/depollution applications, but only a few studies are related to their lubricating properties. In order to investigate a new family of friction reducers, the tribological properties of biochars and derived activated carbons obtained from sugar cane bagasse are investigated. Activated carbons are obtained from either a physical (steam water) or chemical (with phosphoric acid) activation process. The tribological tests show that the activated carbons present very low friction coefficients, close to 0.08. The correlation of textural and tribological investigations shows that the specific surface area of the compounds as well as the microporous and mesoporous domain extensions are key parameters to optimize the friction reduction properties of activated carbons. The friction properties of the compounds are improved if the mesoporous domain extension is above 40% of the total porous volume. This study shows that local biomass waste valorization is possible and that sugar cane bagasse-derived activated carbons appear as interesting new friction reduction additives for lubricants.

Development of a patient-specific model of the human coronary system for percutaneous transluminal coronary angioplasty balloon catheter training and testing

BackgroundTo treat stenosed coronary arteries, percutaneous transluminal coronary angioplasty (PTCA) balloon catheters must combine pushability, trackability, crossability, and rewrap behavior. The existing anatomic track model (ASTM F2394) for catheter testing lacks 3D morphology, vessel tortuosity, and compliance, making evaluating performance characteristics difficult. This study aimed to develop a three-dimensional patient-specific phantom (3DPSP) for device testing and safe training for interventional cardiologists.MethodsA range of silicone materials with different shore hardnesses (00–30–45 A) and wall thicknesses (0.5 mm, 1 mm, 2 mm) were tested to determine compliance for creating coronary vessel phantoms. Compliance was assessed using optical coherence tomography (OCT) and compared to values in the literature. Stenosis was induced using multilayer casting and brushing methods, with gypsum added for calcification. The radial tensile properties of the samples were investigated, and the relationship between Young’s modulus and compliance was determined. Various methods have been introduced to approximate the friction between silicone and real coronary vessel walls. Computerized tomography (CT) scans were used to obtain patient-specific anatomy from the femoral artery to the coronary arteries. Artery lumens were segmented from the CT scans to create dissolvable 3D-printed core models.ResultsA 15A shore hardness silicone yielded an experimental compliance of 12.3–22.4 mm2mmHg·103\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\frac{m{m}^{2}}{mmHg}\\cdot {10}^{3}$$\\end{document} for stenosed tubes and 14.7–57.9 mm2mmHg·103\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\frac{m{m}^{2}}{mmHg}\\cdot {10}^{3}$$\\end{document} for uniform tubes, aligning closely with the literature data (6.28–40.88 mm2mmHg·103\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\frac{m{m}^{2}}{mmHg}\\cdot {10}^{3}$$\\end{document}). The Young’s modulus ranged from 43.2 to 75.5 kPa and 56.6–67.9 kPa for the uniform and calcified materials, respectively. The dependency of the compliance on the wall thickness, Young’s modulus, and inner diameter could be shown. Introducing a lubricant reduced the silicone friction coefficient from 0.52 to 0.13. The 3DPSP was successfully fabricated, and comparative analyses were conducted among eight commercially available catheters.ConclusionThis study presents a novel method for crafting 3DPSPs with realistic mechanical and frictional properties. The proposed approach enables the creation of comprehensive and anatomically precise setups spanning the right femoral artery to the coronary arteries, highlighting the importance of such realistic environments for advancing medical device development and fostering safe training conditions.

Effect of WC content on the microstructure and properties of AlCoCrFeNi2.1 eutectic high entropy alloy coating prepared by ultra-high speed laser cladding technology

AlCoCrFeNi2.1 eutectic high entropy alloy coating with different WC content were prepared on 304 stainless steel surface by ultra-high speed laser cladding technology. Microstructure, phase distribution, Microhardness, friction, and wear properties were analyzed to investigate the influence mechanism of WC on the properties of alloy coatings. The results indicate that the addition of WC results in refined crystalline strengthening. The decomposition of WC leads to the formation of W2C and Cr23C6, which contribute to solid solution strengthening and second-phase strengthening. With increasing WC content, a noticeable improvement in microhardness and wear resistance properties is observed.

Novel injectable adhesive hydrogel loaded with exosomes for holistic repair of hemophilic articular cartilage defect

Hemophilic articular cartilage damage presents a significant challenge for surgeons, characterized by recurrent intraarticular bleeding, a severe inflammatory microenvironment, and limited self-repair capability of cartilage tissue. Currently, there is a lack of tissue engineering-based integrated therapies that address both early hemostasis, anti-inflammation, and long-lasting chondrogenesis for hemophilic articular cartilage defects. Herein, we developed an adhesive hydrogel using oxidized chondroitin sulfate and gelatin, loaded with exosomes derived from bone marrow stem cells (BMSCs) (Hydrogel-Exos). This hydrogel demonstrated favorable injectability, self-healing, biocompatibility, biodegradability, swelling, frictional and mechanical properties, providing a comprehensive approach to treating hemophilic articular cartilage defects. The adhesive hydrogel, featuring dynamic Schiff base bonds and hydrogen bonds, exhibited excellent wet tissue adhesiveness and hemostatic properties. In a pig model, the hydrogel could be smoothly injected into the knee joint cartilage defect site and gelled in situ under fluid-irrigated arthroscopic conditions. Our in vitro and in vivo experiments confirmed that the sustained release of exosomes yielded anti-inflammatory effects by modulating macrophage M2 polarization through the NF-κB pathway. This immunoregulatory effect, coupled with the extracellular matrix components provided by the adhesive hydrogel, enhanced chondrogenesis, promoted the cartilage repair and joint function restoration after hemophilic articular cartilage defects. In conclusion, our results highlight the significant application potential of Hydrogel-Exos for early hemostasis, immunoregulation, and long-term chondrogenesis in hemophilic patients with cartilage injuries. This innovative approach is well-suited for application during arthroscopic procedures, offering a promising solution for addressing the complex challenges associated with hemophilic articular cartilage damage.

Effect of carbonitride on the friction and wear properties of M50NiL steel after sequential carburizing and nitriding treatment

In this work, M50NiL steel was carburized at 950 ℃ for 1 h (C samples) and subsequently nitrided at 520 ℃ for 7 h (CN samples). The carbonitrides of the samples that underwent the sequential carburizing and nitriding treatment were observed before and after wear and analyzed via SEM, FIB, and TEM. The friction and wear properties of the CN samples were compared with those of the C samples. The results show that the surface hardness and surface residual stress of the CN samples were 1.6 and 4.2 times greater than those of the C samples, respectively, i.e., the CN samples were less likely to spall during wear. The carbonitride particle sizes of the CN samples were 100–500 nm before wear and less than 10 nm after wear, indicating that carbonitrides enhanced the wear resistance of the CN samples. The wear area of the CN samples decreased by 95.6 % at 20 N and 87.4 % at 40 N.

The Lubricity of Gases

A sealed reciprocating tribometer has been used to study the influence of different gaseous environments on the friction and wear properties of AISI52100 bearing steel at atmospheric pressure and 25 °C. Helium, argon, hydrogen, carbon dioxide and nitrogen all give high friction and wear, suggestive of very little, if any tribofilm formation under the conditions studied. Dry air and oxygen also give high friction, slightly lower than the inert gases, but produce extremely high wear, much higher than the inert gases. This is characteristic of the phenomenon of “oxidational wear”. The two gases ammonia and carbon monoxide give relatively low friction and wear, and XPS analysis indicates that this is due to the formation of adsorbed ammonia/nitride and carbonate films respectively. For the hydrocarbon gases studied, two factors appear to control friction and wear, degree of unsaturation and molecular weight. For the saturated hydrocarbons, methane and ethane give high friction and wear but propane and butane give low friction after a period of rubbing that decreases with molecular weight. The unsaturated hydrocarbons all give an immediate reduction in friction with correspondingly low wear. Raman analysis shows that all the hydrocarbons that reduce friction and wear form a carbonaceous tribofilm on the rubbed surfaces.Graphical

Molybdenum Disulfide (MoS2) Film Formation and Friction Properties of Molybdenum Phosphate Additive in Combined Condition with Zinc Dialkyldithiophosphate (ZnDTP)

This article describes experimental studies on low friction film formation of molybdenum phosphate (MoP) in combination with zinc dialkyldithiophosphate (ZnDTP). The spinning type friction tests were conducted, and in the test procedure, the test using ZnDTP containing oil was conducted following the test using MoP oil. The results showed that after switching to ZnDTP, the friction coefficient steeply decreased and reached approximately 0.06 in 1,353 ppm of sulfur concentration, and minimum friction coefficient depended on the concentration of sulfur in the oil with ZnDTP. Moreover, it is shown that the friction coefficient gradually increased, and that the coefficient at 1 h after switching to ZnDTP corresponded to that in ZnDTP alone. Raman spectroscopy demonstrated that, at 5 min after switching to ZnDTP, the molybdenum disulfide (MoS2) film was formed on the contact surface. Also, energy dispersive x-ray spectroscopy (EDX) analysis results indicated that at 1 h after switching to ZnDTP, the film derived from ZnDTP was composed of phosphorus, oxygen, and sulfur. These results suggest the film formation mechanism of MoS2: molybdenum oxide, such as iron (II) molybdate (FeMoO4), formed in the test of MoP, was then transformed into MoS2 by sulfur or a sulfur containing compound from ZnDTP decomposition.

Effects of Different Rare Earth Oxides on the Physical, Friction and Wear Properties of ZrC-Cu Composites

Effects of Different Rare Earth Oxides on the Physical, Friction and Wear Properties of ZrC-Cu Composites

Multi-criteria Optimization for Wear and Friction Properties of Self-Lubricating Al6082-T6/GNP/TiB2 Hybrid Composites

Multi-criteria Optimization for Wear and Friction Properties of Self-Lubricating Al6082-T6/GNP/TiB2 Hybrid Composites

Preparation and friction properties of SiC-Al2O3/2A50 co-continuous composites

This study investigated the preparation of SiC porous ceramics using an organic foam impregnation-high temperature sintering process. To address the poor wettability of SiC ceramics when used as the reinforcement phase, the surface of SiC porous ceramics was modified with Al2O3. SiC-Al2O3/2A50 co-continuous composites were then fabricated by infiltrating 2A50 aluminum alloy into the SiC-Al2O3 porous ceramics under pressure. Microstructural observations, along with friction, wear performance, and thermal stability test, demonstrated that Al2O3 surface modification significantly enhances the friction and wear performance as well as the thermal stability of the co-continuous composites. The prepared SiC-Al2O3/2A50 co-continuous composite exhibited excellent wear resistance, good thermal stability and stable bonding at heterogeneous interfaces. Compared to 38CrSi steel, the SiC-Al2O3/2A50 co-continuous composite not only offers the advantage of reduced weight but also shows a significantly lower wear rate of 9.3 × 10−5 mm3/N·min under a 50 N load. These findings suggest that the SiC-Al2O3/2A50 co-continuous composite has the potential to replace 38CrSi steel as a wear-resistant material.

Preparation and tribological properties of PAI/PTFE@Mg-Al LDH polymer-based solid self-lubricating materials

PAI/PTFE composites with 1 %, 2 %, 3 %, 4 % and 5 % of Magnesium aluminum hydrotalcite (Mg-Al LDH) particles were prepared by DC electric field-assisted hot-pressing sintering. The friction and wear properties of the composites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), water contact angle and UMT-5 friction and wear tests. The effect of the amount of Mg-Al LDH particles added on the physical properties and friction and wear properties of the composites were analyzed. Experimental results showed that the friction and wear properties of PAI/PTFE composite films can be improved by adding appropriate Mg-Al LDH particles. Among them, The PAI/PTFE polymer based solid lubrication containing 3 % Mg-Al LDH has the best friction coefficient and wear amount, the average friction coefficient is 0.0962 and the wear extent is 1.47×10−5 g. The improved tribological properties of the composite films are mainly due to the excellent mechanical properties of Mg-Al LDH and the good lubrication properties of PTFE.

Friction and wear properties of D-gun sprayed CrFeNiAl0.3Ti0.3-Ag-SrSO4 high entropy alloy matrix self-lubricating coating at elevated temperature

CrFeNiAl0.3Ti0.3-10 wt% Ag-(10−30) wt% SrSO4 high entropy alloy matrix self-lubricating coatings were fabricated using detonation spray technique and tribological characteristics of CrFeNiAl0.3Ti0.3-10 wt% Ag-(10−30) wt% SrSO4 coatings were explored from 25 to 1000 °C. The Ag and SrSO4 lubricants have good compatibility with CrFeNiAl0.3Ti0.3 matrix phase. The bond strength and hardness of CrFeNiAl0.3Ti0.3-Ag-SrSO4 coatings are 30 ∼ 65 MPa and 461 ∼ 535 HV, respectively. Meanwhile this coating exhibited good tribological performance across the wide temperature range and achieved the lowest friction coefficients of 0.29 ∼ 0.49 and wear rates of 2.68 ∼ 11.82 × 10−5 mm3/Nm when SrSO4 content is 10 wt%. Between 25 and 600 °C, SrSO4 and Ag lubricants, can effortlessly create complete lubricating films, preventing three-body wear and plastic deformation. At 800 and 1000 ℃, SrSO4 inflicts a significant impact on the formation of the oxide tribo-layer. When SrSO4 content is 10 wt%, it is feasible to form a compacted oxide layer containing SrCrO4, SrAl2O4 and SrTiO3, reducing the friction and wear. With further increasing SrSO4 content to 20 wt% and 30 wt%, the excessive SrSO4 leads to a detrimental on the compactness of oxide tribo-layer, increasing the friction and wear.

Structural, mechanical, and oxidation resistance properties of double glow plasma Ta[sbnd]W alloys

To enhance the performance of surface coatings on weaponry, TaW alloy layers with various W contents (7, 11.5, 13, 14, 14.5 and 16 at. %) were prepared on the surface of a PCrNi3MoVA gun steel substrate using double-glow plasma surface metallurgy technology. Mechanical properties, friction wear, and oxidation resistance were studied using scratch, hardness, and tribometer testers. The mechanical properties, interfacial properties, and effects on the oxidation performance of the gun steel substrate of the TaW alloy layer were calculated using first principles. The results indicated that the surface and cross-sectional microstructures of the TaW alloy layers were dense and free from obvious defects. With increasing W content, the thickness, hardness, and adhesive strength of the TaW alloy layer increased, and the coefficient of friction and wear rate decreased. The results of the calculations indicate that an increase in the W content enhances the elastic modulus of the TaW alloy and improves its brittleness, strength, and hardness. Doping with Ta and W atoms can increase the vacancy formation energy of Fe atoms in the Fe supercell, the adsorption energy of O atoms on the surface of Fe(110), and the diffusion barrier of O atoms in the Fe supercell and on the Fe(110) surface. Interdoping of Ta, W and Fe atoms at the Fe(110)/Ta-W(110) interface improved the bonding strength and stability of the interface, and the FeTa and FeW chemical bonds formed at the Fe(110)/Ta-W(110) interface ensured stable bonding at the interface. The incorporation of W into the TaW alloy layer enhanced both the mechanical and frictional properties of the alloy. It is well established that TaW alloys improve the antioxidant properties of gun steel substrates, thereby enhancing the performance of coatings on weaponry.

Spatiotemporal dominance of afterslip and viscoelastic relaxation revealed by four decades of post-1973 Luhuo earthquake observations

Measuring surface displacements driven by afterslip and viscoelastic relaxation following large earthquakes enables inferring frictional and rheological properties of Earth's outermost layers where hazardous earthquakes occur. However, the two concurrent mechanisms generate similar and intertwined surface deformations, complicating the extraction of physical information from the measurements. Here, we quantify the spatiotemporal dominance of co-evolving afterslip and viscoelastic relaxation following the 1973 Ms 7.6 Luhuo earthquake in eastern Tibet, using 42 years (1976‒2018) of fault-crossing short-baseline observations. The finite-fault slip of this M7+ earthquake was constructed from triangulation data measured in 1961‒1975. Based on the model incorporating two postseismic relaxation mechanisms and calibrated by the measurements over four decades, we show that, in the temporal domain, afterslip may produce geodetically measurable deformations (>1.5 mm/yr) in local near-field regions even 20 years after the mainshock, with spatially broader impact within ∼10 years. Viscoelastic relaxation may last for nearly six decades, imposing a broad influence for three decades. In the spatial domain, afterslip may produce deformations within ∼2 times the seismogenic depth (SD; 20 km) from the fault, but dominantly in the near-field of ∼1 times the SD. In contrast, viscoelastic relaxation may affect a much wider region reaching 200 km. While afterslip and viscoelastic relaxation collectively affected the region ∼2 times the SD from the fault in the early postseismic period, their resulting deformations gradually separated in space with time, with afterslip-induced deformation shrinking toward the fault, and surface deformation caused by viscoelastic relaxation concentrating in the mid-field, ∼2–3 times the SD from the fault. Their spatiotemporal partitioning helps better learn fault frictional properties and lithospheric rheology based on geodetic data acquired from different domains.