Fact-checked by Grok 2 weeks ago

Galling

Galling is a severe form of adhesive wear characterized by the adhesion and subsequent tearing of material between two sliding surfaces, often leading to seizure or cold welding, particularly in unlubricated metallic contacts under high pressure and low sliding speeds.^[1] This phenomenon typically occurs when the protective oxide layers on metal surfaces are disrupted, exposing reactive underlying material that bonds upon contact, resulting in material transfer and surface damage.^[2] Galling is most prevalent in materials like stainless steel, titanium, and aluminum, where similar compositions exacerbate adhesion.^[1] In mechanical engineering applications, galling commonly affects threaded fasteners, such as bolts and nuts, during assembly, where excessive torque or high-speed tightening can cause threads to seize, potentially leading to fastener failure or stripped components.^[3] It also poses significant challenges in sheet metal forming processes, where tool-sheet interactions under compression generate galling through prow formation and material pickup on dies.^[4] The issue is particularly critical in industries like aerospace, automotive, and manufacturing, as it can compromise joint integrity, increase friction, and necessitate costly repairs or replacements.^[5] Prevention strategies focus on mitigating adhesion through material selection, such as pairing dissimilar metals or alloys with differing hardness, and applying lubricants like molybdenum-based compounds to maintain oxide layers and reduce friction.^[1] Surface treatments, including coatings (e.g., dry film lubricants or platings like zinc), and optimized assembly practices—such as slower tightening speeds and clean, aligned threads—further enhance resistance.^[3] Standardized tests, like ASTM G98, are used to evaluate and compare galling resistance in materials, aiding design decisions in high-wear environments.^[6]

Fundamentals

Definition and Characteristics

Galling is a form of surface damage arising between sliding solids, distinguished by macroscopic, usually localized, roughening and/or surface tearing of one or both sliding surfaces, as defined in the ASTM G40 standard on terminology relating to wear and erosion.^[7] This phenomenon arises when localized adhesion between asperities on the mating surfaces leads to severe surface damage, often resulting in the surfaces locking together and preventing further relative motion.^[8] Unlike other wear modes, galling specifically involves adhesion-driven mechanisms akin to cold welding, where material from one surface adheres to and is torn from the other, rather than material removal through mechanical cutting in abrasion or particle impact in erosion.^[9] Key characteristics of galling include the development of macroscopic roughening, localized tearing, and the formation of protrusions or excrescences on the affected surfaces, which can evolve into raised lumps if unchecked.^[10] Microscopically, these features manifest as irregular surface topography with material buildup, often accompanied by increased surface hardness in the galled regions due to work hardening.^[11] The process typically occurs in high-load, low-speed sliding contacts where lubrication is insufficient to prevent direct metal-to-metal interaction.^[12] Visually, galling appears as shiny, burnished patches with irregular bulges or tears on the surface, while tactile signs include a sudden increase in friction, such as elevated torque requirements during assembly of threaded fasteners, where the threads may bind or seize. In threaded applications, this can lead to detectable resistance that exceeds normal tightening forces, signaling the onset of material transfer and potential failure to fully engage or disengage components.^[13]

Historical Development

The formal study of galling began to take shape in the mid-20th century within the emerging field of tribology, with significant contributions from researchers Frank Philip Bowden and David Tabor. In their seminal 1950 work, The Friction and Lubrication of Solids, they developed the adhesion theory of friction, demonstrating through experiments that frictional forces between clean metal surfaces arise primarily from the shearing of adhesive junctions at asperity contacts, providing an early mechanistic framework for understanding galling as a severe manifestation of adhesive wear. Their research in the 1940s and 1950s, including studies on the real area of contact and the role of surface films, laid the groundwork for later galling investigations by highlighting how adhesion dominates under high loads and poor lubrication.^[14]^[15] Key milestones in the 1960s included studies on cold welding in vacuum environments, which influenced galling models by illustrating extreme adhesion between uncontaminated metal surfaces. NASA-funded research during this period, amid early space exploration, revealed that in ultra-high vacuum, clean metals could bond solidly without heat or fusion, attributing mechanism failures to such adhesion and prompting models that linked vacuum-induced cold welding to atmospheric galling processes involving partial surface films. These findings, detailed in reports like the 1967 NASA survey on adhesion in space, underscored the role of environmental factors in adhesive wear, bridging vacuum experiments to terrestrial galling scenarios.^[16] By the 1970s, galling received standardized definition through tribological nomenclature, culminating in the development of the ASTM G40 standard. Originally approved in 1973, this standard formalized galling as "a form of surface damage arising between sliding solids, distinguished by macroscopic, usually localized, roughening and/or tearing of one or both sliding surfaces," establishing a consistent terminology for wear and erosion studies and facilitating reproducible testing in engineering contexts.^[17]

Mechanisms of Galling

Adhesion and Wear Processes

Galling originates from the initial contact between surface asperities of sliding metal components under applied load, where the localized pressures exceed the yield strength of the materials, causing plastic deformation and the formation of adhesive junctions at these points. This process is governed by the adhesion theory of friction, in which the real area of contact, A_r, is a small fraction of the apparent contact area and increases with load according to A_r = F / H, where F is the normal force and H is the hardness of the softer material.^[18] The junctions form preferentially at clean metal interfaces after the disruption of native oxide layers or contaminants, enabling direct atomic interaction between the lattices of the mating surfaces. Once formed, these junctions undergo shear during relative motion, leading to material transfer from one surface to the other in a process analogous to cold welding, where cohesive forces bind the metals without melting. The shear strength of the adhesive junctions, \tau, can be approximated as \tau = s \cdot A_r, where s is the interfacial shear strength, often on the order of the yield shear stress of the material, approximately \sigma_y / \sqrt{3} based on von Mises criterion, with \sigma_y as the yield stress.^[19] This transfer manifests as wear particles or build-up on the harder surface, exacerbating friction and further adhesion in subsequent cycles.^[20] Frictional heat generated at the interface during sliding can elevate the local temperature, softening the materials and promoting atomic diffusion across the junction, strengthening the metallurgical bond. This thermal effect transitions the process from mechanical adhesion to enhanced chemical bonding, accelerating material transfer and surface degradation. The progression culminates in macroscopic seizure when accumulated transferred material disrupts smooth sliding, leading to unstable contact and potential locking of components.^[20] At the microscopic level, galling is characterized by roughening and the formation of protrusions or excrescences on the surfaces, as defined by ASTM G40, where localized roughening creates lumps or projections accompanied by roughening of the opposing surface.

Material and Environmental Factors

Material factors play a critical role in determining galling susceptibility, primarily through properties that influence adhesion and material transfer during sliding contact. High ductility, characteristic of face-centered cubic (FCC) crystals such as aluminum, promotes galling by enabling extensive plastic deformation and prow formation at asperities, facilitating severe adhesive wear.^[21] Low stacking fault energy can improve resistance to galling by enabling alternative deformation modes, such as twinning, which accommodate strain without excessive adhesion. The stability of surface oxide layers is another key factor; thin, easily disrupted oxide films, as found on stainless steels, fail to prevent direct metal-to-metal contact, thereby increasing galling tendency under load.^[3] Crystal structure further modulates galling behavior, with FCC metals generally exhibiting greater resistance than body-centered cubic (BCC) metals due to their multiple slip systems that accommodate deformation more readily without catastrophic adhesion. For instance, copper (FCC) demonstrates lower galling severity compared to iron (BCC), where fewer active slip planes at room temperature contribute to higher frictional locking.^[2] In certain materials, such as heat-treated steels, galling threshold loads increase with material hardness; for example, self-mated surfaces with Vickers hardness (H_v) exceeding 450 kg/mm² show significantly reduced incidence due to limited plastic flow and asperity penetration.^[2] Environmental conditions profoundly affect galling by altering interfacial interactions and oxide formation dynamics. High contact loads amplify stress at asperities, promoting adhesion and material transfer, with damage escalating linearly until plateauing around 10,000 N in unlubricated conditions.^[2] Low sliding speeds worsen galling by allowing prolonged contact time for atomic bonding, whereas elevated temperatures enhance adhesion through reduced shear strength and accelerated diffusion at the interface.^[22] The absence of lubrication eliminates boundary films that shear easily, directly exposing metals to galling, while vacuum or inert atmospheres exacerbate the process by inhibiting protective oxide layer reformation, leading to cold welding at loads as low as those insufficient in air.^[2]

Incidence in Engineering

Common Applications and Sites

Galling frequently occurs in threaded fasteners, such as bolts and screws, where high frictional forces and pressures during tightening cause adhesion and potential seizure of mating threads.^[1] It is also prevalent in valves and bearings within high-load assemblies, arising from prolonged metal-to-metal contact under compressive and sliding conditions that promote surface material transfer.^[23] In the automotive industry, galling commonly affects engine components like pistons and synchronizing rings, contributing to wear in transmissions and overall system failures under operational loads.^[24] Aerospace applications, particularly those involving titanium fasteners, encounter galling in structural joints and assemblies due to the alloys' reactivity and high-stress environments.^[25] The manufacturing sector experiences galling in sheet metal forming processes and extrusion dies, where tool surfaces interact with workpieces under elevated pressures, leading to buildup and disrupted production.^[26] Specific scenarios prone to galling include low-speed, high-pressure sliding contacts, such as in hydraulic fittings during connection or in cutting tools processing soft metals, where insufficient relative motion exacerbates adhesion.^[27] Unlubricated stainless steel threads during assembly carry a high risk of galling, often resulting in significant fastener damage and assembly inefficiencies.^[3] In emerging fields like additive manufacturing, galling influences post-processing, notably in the tribological behavior of AM-produced hot forming tools, where abrasion and adhesion degrade performance during use.^[28] Certain materials, such as stainless steel, exhibit heightened vulnerability in these sites due to their surface characteristics.

Susceptible Materials and Alloys

Austenitic stainless steels, such as types 304 and 316, are highly susceptible to galling primarily due to their tendency to work-harden during sliding contact, which promotes adhesive wear and material transfer.^[29] These alloys exhibit low threshold galling stresses in self-mated pairings, typically around 2 ksi, indicating failure under minimal loads without lubrication.^[29] Aluminum alloys like 6061-T6 also demonstrate high susceptibility, galling at low loads owing to their ductility, which facilitates protrusion formation and abrasion against harder counterparts such as tool steels.^[30] Similarly, titanium alloys including Ti-6Al-4V are notoriously prone to galling, with their alpha-beta structure exacerbating adhesion and seizure in unlubricated conditions, often requiring surface treatments for mitigation.^[31] Nickel-based alloys and soft steels fall into the moderately susceptible category, where their intermediate hardness and composition lead to galling under moderate sliding pressures, though less severely than austenitic stainless steels.^[32] In contrast, hardened tool steels like type 440C, copper alloys, and ceramics exhibit strong resistance; for instance, hardened 440C achieves threshold stresses up to 11 ksi in self-mated tests, while ceramics benefit from their high hardness preventing adhesive bonding.^[29] Copper alloys, particularly those with silicon additions, further enhance resistance through improved wear properties in demanding environments.^[33] Galling resistance can be quantified using standards like ASTM G98, which measures threshold galling stress in ksi; aluminum alloys score low (e.g., 6061-T6 with a risk factor of 0.6 on a 0-1 scale where higher indicates greater susceptibility), while resistant materials like Nitronic 60 exceed 50 ksi.^[34]^[29] Pairing effects significantly influence outcomes, with same-material contacts such as stainless steel on stainless steel promoting severe galling due to compatible surface chemistries and hardness, whereas dissimilar pairings like stainless steel on brass reduce risk through mismatched atomic structures and lower adhesion tendencies.^[35] Data on modern materials like composites and nanomaterials remains limited, but initial studies indicate that graphene-reinforced metal composites and graphene-coated surfaces can reduce galling by lowering friction coefficients and enhancing load-bearing capacity in sliding contacts.^[36] Ductility, as a key factor in susceptibility, aligns with these materials' behaviors by enabling plastic deformation and material pickup during contact.^[32]

Prevention and Control

Lubrication and Coatings

Lubricants play a crucial role in preventing galling by forming a protective film that interrupts direct asperity contact between sliding metal surfaces. Greases incorporating molybdenum disulfide (MoS₂) are particularly effective solid lubricants for this purpose, as MoS₂'s layered structure shears easily under load, providing low-friction lubrication even in boundary conditions. These greases are commonly applied in threaded fasteners and high-load assemblies to minimize adhesion and cold welding. Oils supplemented with anti-wear additives, such as zinc dialkyldithiophosphate (ZDDP), chemically react with metal surfaces to create sacrificial phosphate layers, further reducing wear and galling propensity in stainless steels and other alloys.^[37]^[38]^[39] The mechanism underlying lubricant efficacy relies on boundary lubrication, where the lubricant film thickness exceeds 1 μm to separate surface asperities and avoid severe adhesive wear. This regime is illustrated by the Stribeck curve, which depicts the transition from high-friction boundary lubrication—dominated by surface interactions—to lower-friction mixed and hydrodynamic regimes as speed, viscosity, and load vary, thereby optimizing conditions to suppress galling initiation. Maintaining this film integrity is essential, as thinner films (<1 μm) allow direct metal contact, promoting material transfer and seizure.^[40]^[41] Surface coatings offer a durable alternative or complement to lubricants by altering the tribological properties of contacting surfaces. Titanium nitride (TiN) thin films, deposited via physical vapor deposition, achieve hardness values exceeding 2000 HV, enhancing resistance to plastic deformation and abrasive wear while reducing galling in tools and dies. Diamond-like carbon (DLC) coatings, with amorphous carbon structures, further lower the friction coefficient to below 0.1, providing excellent anti-adhesive performance in dry or minimally lubricated environments. For specific applications like threaded components, electroplating with silver imparts inherent lubricity due to its softness and shearability, significantly reducing galling torque—often by 70-90% in high-torque fastening—while phosphate coatings (e.g., manganese phosphate) promote initial break-in and corrosion resistance on ferrous fasteners, cutting galling incidence in assembly processes.^[42]^[43]^[44]^[45]^[46] Despite their benefits, both lubricants and coatings have limitations under extreme conditions. Conventional oil- and grease-based lubricants decompose or evaporate above 300°C, losing film strength and exposing surfaces to galling, while many thin-film coatings like TiN and DLC oxidize or delaminate under high thermal loads or prolonged heavy contact, necessitating selection based on operational temperature and pressure.^[47]

Design and Material Selection

Design strategies for mitigating galling focus on minimizing contact pressures and frictional stresses at sliding interfaces through geometric modifications. Oversized clearances in mating components, such as increasing the gap between threads or shafts by 10-20% beyond nominal tolerances, reduce the effective contact area and prevent cold welding under load. Tapered threads, which gradually increase in diameter along the engagement length, distribute stress more evenly and lower peak pressures compared to straight threads. Helical inserts, often made from softer materials like phosphor bronze, can be incorporated into high-load assemblies to act as a sacrificial barrier, absorbing deformation without galling the primary components. These approaches are particularly effective in threaded fasteners and rotating machinery where direct metal-to-metal contact is unavoidable. Material selection plays a critical role in inherently reducing galling propensity by choosing combinations that limit adhesion and material transfer. Pairing dissimilar metals, such as carbon steel against bronze or aluminum against stainless steel, exploits differences in crystal structure and hardness to minimize galling, as the shear strength mismatch discourages material pickup. Galling-resistant alloys like Inconel 718 or Hastelloy C-276 are preferred for severe-service environments due to their high nickel content and stable oxide layers that inhibit adhesion during sliding. For instance, in chemical processing equipment, selecting titanium for one component and Monel for the mating part has demonstrated near-elimination of galling under corrosive conditions. Avoiding self-mating pairs of high-ductility materials, such as austenitic stainless steels, is essential, as these exhibit severe galling when slid against themselves (detailed in Susceptible Materials and Alloys). Engineering guidelines emphasize maintaining contact pressures below the yield strength of the softer material to stay within the elastic regime and avoid plastic deformation that promotes galling. This threshold, derived from friction and wear models, ensures that local stresses do not exceed the material's capacity for shear without bonding. Additionally, avoiding same-material sliding in ductile pairs prevents the formation of adhesive junctions. These principles are integrated into standards such as ISO 898, which specifies torque limits for fasteners to control preload and prevent excessive thread pressures that could induce galling during assembly. Compliance with ISO 898 has been shown to reduce galling failures in bolted joints by enforcing proof load calculations that cap stress at safe levels.

Advanced Mitigation Techniques

Surface engineering techniques, such as plasma nitriding and Kolsterising, have emerged as effective methods to enhance galling resistance by significantly increasing surface hardness and forming protective diffusion layers. Plasma nitriding of austenitic stainless steels can achieve surface hardness levels exceeding 1200 HV through the formation of expanded austenite phases, while maintaining corrosion resistance.^[48] Kolsterising, a low-temperature carburizing process, similarly yields hardness in the range of 900-1300 HV with case depths typically between 20-40 μm, enabling improved wear resistance without distortion.^[49] These treatments mitigate galling by creating a hard, low-friction surface layer that reduces adhesive transfer during sliding contact.^[50] Finite element modeling (FEM) serves as a computational tool for predicting stress distributions and galling thresholds in engineering components, allowing for proactive design optimization. By simulating contact pressures and plastic deformation, FEM identifies critical zones prone to galling initiation, often under loads exceeding 1000 kPa.^[51] The Archard wear equation, adapted for adhesive-dominated galling, quantifies volume loss as V = k \frac{L S}{H}, where V is wear volume, k is the galling-specific wear coefficient, L is load, S is sliding distance, and H is hardness; this model integrates adhesion probability to forecast material transfer.^[52] In aerospace applications, vacuum testing protocols evaluate titanium alloys' galling susceptibility under low-pressure conditions, where absent atmospheric lubrication exacerbates adhesion. For Ti6Al4V components, such tests reveal accelerated wear against steel counterparts, prompting the development of protective coatings to maintain performance in space environments.^[53] Post-treatments for additively manufactured titanium parts, including laser peening, induce compressive residual stresses up to 1 GPa in surface layers, enhancing fatigue life and indirectly reducing galling propensity by minimizing crack propagation sites.^[54] Post-2021 advancements include nanostructured coatings, such as nanolayered (Cr,V)N films, which can demonstrate improved galling resistance at elevated temperatures depending on vanadium content and conditions, by altering friction mechanisms and reducing material pickup.^[55] Polyurethane-based nanocomposite coatings have shown up to 95% reduction in wear rates under galling conditions, attributed to nanoparticle reinforcement (e.g., alkylated MoS₂).^[56] AI-optimized lubricant formulations, leveraging machine learning to predict friction coefficients, enable tailored additives that lower lubricated wear in simulations, supporting galling mitigation in high-load scenarios.^[57] As of 2024-2025, advancements include Expanite nitrocarburising treatments enhancing hardness and corrosion resistance in stainless steels, and Lubrinox factory-applied permanent lubrication on fasteners to reduce friction and galling.^[58]^[59] Future directions emphasize integrating IoT sensors for real-time monitoring of adhesive wear in machinery, enabling predictive alerts based on vibration and debris analysis to preempt galling onset.^[60] Such systems facilitate proactive interventions, potentially extending component life in dynamic industrial settings.^[61]

References

[1]
What is Galling? - TWI Global
Galling is the term used when two surfaces in contact seize up as a result of cold welding. The problem (also known as 'adhesive wear') is most commonly seen ...
[2]
[PDF] The mechanism, measurement, and influence of properties on the ...
Galling involves prow formation, measured by surface topography. Crystal structure and stacking fault energy are key properties influencing galling.
[3]
[PDF] pem® ref/thread galling - TECH SHEET
Definition – Galling is the seizing or abrading of threads caused by adhesion between sliding surfaces of the fasteners' mating threads.
[4]
[PDF] Characterizing Galling Conditions in Sheet Metal Stamping - NSF PAR
Apr 9, 2024 · Galling is detected by increased pulling force during sheet metal flow. It's caused by material transfer and can be delayed by lubricants. Tool ...
[5]
[PDF] Galling Failures in Pin Joints Greg A. Radighieri - DSpace@MIT
May 18, 2002 · Failure of heavily loaded pin joints is yet to be fully understood and is often generalized as galling failure.
[6]
Elements to Improve Galling Resistance Test Results Using the ...
The ASTM G98 Standard Test Method for Galling Resistance of Materials describes a relatively easy and quick method to screen materials for galling ...
[7]
Interpretation of galling tests - ScienceDirect.com
Galling as defined by ASTM G40 [1] Terms and Definitions relating to wear and erosion, requires the formation of protrusion (excrescences) from a surface ...
[8]
Repeatability Estimation in Galling Resistance Testing | J. Tribol.
Oct 1, 2010 · Galling, as defined by ASTM G40 (1), is a Boolean outcome in any one run of a galling test. Specifically, upon completion of a test, galling is ...
[9]
Chapter 4: Types of Wear and Erosion and Their Mechanisms
Overall, galling is a severe form of adhesive wear characterized by the ... abrasive wear, adhesive wear, erosion, fretting corrosion, fretting wear ...
[10]
Surface damages during galling phenomenon under a sliding ...
The definition according to ASTM G40-17 is "a form of surface damage arising between sliding solids, distinguished by macroscopic, usually localized ...
[11]
[PDF] An experimental investigation of galling phenomenon ... - HAL
Aug 31, 2022 · Galling, defined as a surface damage arising between surface sliding solids distinguished by macroscopic, usually localized, roughening and ...
[12]
Galling | About Tribology - Tribonet
Galling is a severe type of adhesive wear, often catastrophic, caused by high stresses, poor lubrication, and high temperatures, resulting in material transfer.
[13]
Thread Galling | How to Prevent It - Dicronite
Jun 6, 2023 · As galling progresses, the threads become more seized and locked together, requiring higher levels of torque to tighten or loosen the fastener.Missing: visual tactile
[14]
[PDF] Galling phenomena in metal forming - HAL-UPHF
Apr 28, 2022 · Galling has been recognized as a form of seizure on frictional surfaces that have become thermally or mechanically unstable [6–9]. Further- more ...
[15]
The Friction and Lubrication of Solids - F. P. Bowden; D. Tabor
This book is a landmark in tribology, covering solid friction, lubrication, wear, and the area of contact between solids.
[16]
Mechanism of Metallic Friction as described by Bowden and Tabor
Feb 18, 2025 · Experimental investigations indicate that friction primarily arises from shearing or adhesion of the softer material in contact with the harder surface.
[17]
[PDF] adhesion in the space environment
This report presents a comprehensive literature survey of adhesive bonding (cold welding) in the space environment. Space characteristics are summarized and ...Missing: galling | Show results with:galling
[18]
[PDF] G40 − 22a
Nov 1, 2022 · Originally approved in 1973. Last previous edition approved in 2022 as G40 – 22. DOI: 10.1520/G0040-22A. 2 For referenced ASTM standards ...
[19]
The area of contact between stationary and moving surfaces - Journals
(2019) An experimental method for quantitative analysis of real contact area based on the total reflection optical principle*, Chinese Physics B, 10.1088/1674- ...<|control11|><|separator|>
[20]
Bowden and Tabor - an overview | ScienceDirect Topics
Contact occurs at the asperities, implying that the real contact area is ... shear strength s, then the friction force due to adhesion will be given by.
[21]
(PDF) Galling phenomena in metal forming - ResearchGate
Aug 6, 2025 · Many metals undergo a form of wear known as galling, in which adhesion between surfaces causes macroscopic protrusions to form, increasing ...Missing: seminal | Show results with:seminal
[22]
Numerical prediction of the galling of aluminium alloys in cold strip ...
The galling propensity of aluminium and aluminium alloys is due to the brittle nature of the oxide layer. Deformation will cause the oxide layer to break up and ...Missing: FCC | Show results with:FCC
[23]
Thread Galling - Fastenal
Galling, often referred to as a cold-welding process, can occur when the surfaces of male and female threads are placed under heavy pressure.
[24]
Application Spotlight: Galling Resistance - A&A Coatings
The automotive industry: The galling process can occur in the piston and synchronizing rings of automobiles, causing more engine and transmission breakdowns.
[25]
[PDF] Galling and Seizing Characteristics of Titanium and Titanium-Base ...
For titanium vs. titanium, if galling has started on one surface it does not take long for the other surface to follow suit.
[26]
Galling phenomena in metal forming - SciOpen
Nov 13, 2020 · Galling phenomena in metal forming not only affect the quality of the engineered surfaces but also the success or failure of the ...Missing: term | Show results with:term
[27]
Hydraulic Fittings: A Galling Metallurgical State of Affairs
Oct 28, 2015 · When two pieces of stainless steel are forced together, the passivation layer gets scraped off, allowing parts to gall (or 'weld'). In fact, any ...
[28]
[PDF] Tribological characterisation of additively manufactured hot forming ...
Aug 27, 2020 · The main wear mechanisms for AM materials were galling and abrasion at both temperatures. Abrasion is more severe for the AM steels in ...
[29]
[PDF] REVIEW OF THE WEAR AND GALLING CHARACTERISTICS OF ...
ASTM published (2) a number of papers presented at the Symposium on the Selection and. Use of Wear Tests for Metals, held November 20, 1975 in New. Orleans, LA.
[30]
Galling in aluminum alloys and Duralcan aluminum matrix composites
The unreinforced 6061 alloy, exhibited galling at low loads with protrusions forming on the hard steel slider that caused abrasion of the aluminum alloy.
[31]
Investigation of surface treatments for galling protection of titanium ...
Titanium is notoriously susceptible to galling, and although significant benefits can be gained by alloying, titanium alloys such as the commonly used Ti6Al4V ( ...
[32]
[PDF] THE MECHANISM, MEASUREMENT, AND INFLUENCE OF ... - OSTI
Stainless steels and other high nickel - high chromium containing alloys are employed. Many of these materials are found to be especially prone to galling.
[33]
[PDF] SOME NICKEL-COPPER CASTING ALLOYS
Alloy 506 (3% Si) combines high strength and wear resistance. Alloy 505 (4% Si) is employed where wear resistance and excep- tional resistance to galling are ...
[34]
Everything You Should Know About Thread Galling - Spex
Jul 10, 2025 · Salt spray exposure accelerates galling onset by 40%; Vacuum environments show 3x higher galling susceptibility. Galling can also happen over ...Missing: inert exacerbate
[35]
[PDF] galling resistance of s³p-treated stainless steels - Bodycote
Method for Galling Resistance of Materials”. The classification number is the threshold galling stress. The higher it is, the better the galling resistance.
[36]
What Causes Metal Galling & How to Prevent It? - WayKen
Jun 13, 2025 · Galling is a severe kind of adhesive wear on metal surfaces that slide against each other under high pressure and temperature.
[37]
Mechanical response and wear behavior of graphene reinforced ...
In this study, graphene reinforced Inconel 718 composites were produced using a novel hybrid accumulative roll bonding (ARB)–gas tungsten arc welding (GTAW)Missing: nanomaterials | Show results with:nanomaterials
[38]
Tribological Behaviors of Graphene and Graphene Oxide as Water ...
Jan 29, 2018 · The tribological behaviors of graphene and graphene oxide (GO) as water-based lubricant additives were evaluated by use of a reciprocating ...
[39]
[PDF] Molybdenum Disulfide - The Ideal Solid Lubricant and Anti-Galling ...
Molybdenum disulfide is an ideal anti-galling compound because of its combination of high compressive strength and its adherence (ability to fill or level) to ...
[40]
Development of chloride-free oil with sulfur-based EP additive for ...
Oil with a chlorinated extremely-pressure additive (EP-additive) is effective to prevent galling in cold forming for stainless steel. However environmental ...<|separator|>
[41]
https://www.tribonet.org/webinar/evaluating-the-stribeck-curve-in-the-boundary-lubrication-regime-using-a-force-controlled-tribometer-3/
[42]
Understanding the lubrication regime phenomenon and its influence ...
Boundary lubrication may alternatively be characterized as a regime where the load is borne by the roughness of the surface rather than the lubricant itself [15] ...
[43]
Evaluating the Stribeck Curve in the Boundary Lubrication Regime ...
The Stribeck curve is a key concept in tribology that explains how friction, viscosity, and load interact in different lubrication conditions.
[44]
[PDF] "Tin Coatings for Wear Resistance and Gold-like Decorative Coatings"
TiN coatings typically have hardnesses of about 2200 kg/mm2 (Vickers hardness), which is three times that of fully hardened tool steel.
[45]
Vanadium nitride and titanium nitride coatings for anti-galling ...
1. Cathodic arc TiN coating exhibits the highest hardness and can withstand the highest critical load 1 (Lc1) of all the coatings tested. This indicates the ...Vanadium Nitride And... · Tool And Workpiece Materials · Coating Properties
[46]
[PDF] Diamond-like carbon coatings (DLC)
Typical coating thicknesses: 1 µm to 10 µm. Low coefficients of friction (COF). High wear resistance. High level of hardness coupled with above-average high ...
[47]
FAQ 5: Galling and its Control
Surfaces treated so that they are harder, for example, hard chrome plated, nitrided, carburised or cold worked surfaces are usually less susceptible to galling.Missing: layer stability
[48]
Influence of surface roughness and phosphate coating on galling ...
Apr 15, 2020 · It was shown that manganese phosphate coatings can reduce abrasive wear by one third, eliminate adhesive wear at elevated temperature [12] and ...
[49]
Solid Lubrication at High-Temperatures—A Review - PMC - NIH
Feb 24, 2022 · However, the oils and greases limitation are their decomposing at temperatures beyond 300 °C and their harmful effects on environmental and ...
[50]
Low temperature plasma nitriding of 316 stainless steel by a saddle ...
Aug 8, 2025 · Nitriding by plasma is a promising method for surface treatment to improve hardness, corrosion, wear and fatigue resistance of materials ...
[51]
Kolsterising - Hardening of Stainless Steel - Bodycote
Surface hardness range 900-1300 HV0.05 · Improved resistance to surface wear environments such as sliding · FDA MASTER FILE MAINTAINED AND BIOCOMPATIBLE · Improved ...Missing: plasma nitriding prevention case
[52]
The frequently asked questions of Kolsterising ® - The Bodycote Blog
Jun 17, 2017 · Which diffusion depths can be achieved? This depends on the material type and process chosen. It is generally a case depth of between 10 and 40 ...Missing: plasma prevention
[53]
Rudiment of 'galling: Tribological phenomenon' for engineering ...
Simultaneously, it also deals with the novel and advanced techniques for the mitigation of galling such as design rectification using FEA models, ...
[54]
Modelling of Wear and Galling in Press Hardening Simulations
Nov 27, 2017 · The modified Archard wear model was rewritten as Equation 3.7. h = V. A= g ×. F. A ×s = g × P × s. (3.7) where h is the galling height in [m], V ...
[55]
[PDF] Reducing Wear of Steel Rolling Against Ti6Al4V Operating in Vacuum
In this project alterative materials and coatings were tested with intent to reduce wear and debris when steel has a misaligned rolling contact against Ti6Al4V.
[56]
Laser peening: A tool for additive manufacturing post-processing
This work evaluates the ability of shot and laser peening to enhance the fatigue lifetime and strength of AM parts.Missing: galling | Show results with:galling
[57]
High temperature friction and galling properties of nanolayered (Cr ...
Jul 25, 2023 · Results show that (Cr,V)N coatings do not necessarily improve galling resistance, being strongly dependent on V concentration and contact temperature.
[58]
Comparative Study on Galling and Antiwear Behavior of ...
The PU-based nanocomposite coatings showed enhanced galling resistance at room temperature. The reciprocating wear studies showed a significant reduction in ...
[59]
Using Artificial Intelligence to Predict Lubricated Friction in ...
Aug 3, 2023 · The present article analyses the use and optimization of an Artificial Intelligence (AI) algorithm for predicting the friction coefficient (CoF) in lubricated ...
[60]
WearDetect IOT – Gill Sensors & Controls
WearDetect IoT brings you proactive, real-time maintenance insights to optimise operations and safeguard your machinery.
[61]
A novel IoT sensor and evolution model for grinding mill liner wear ...
This study developed a novel IoT wear sensor and a Discrete Element Modelling coupled methodology to predict and continuously evolve shell liner's wear pattern.<|control11|><|separator|>