Improvement in galling performance through surface engineering

Podgornik, Bojan; Vižintin, J.; Hogmark, Sture

doi:10.1179/174329406x122946

Cited by 21 publications

(10 citation statements)

References 12 publications

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“…16 On the other hand, the best results are obtained using plasma nitriding. 25,34 The plasma nitriding of tool steel gives up to 40 % lower friction against austenitic stainless steel and up to 50 % better galling resistance, as compared to hardened tool steel, as shown in Figure 3. However, the selection of the proper plasma-nitriding parameters and post-treatment conditions is crucial.…”

Section: Cold Sheet-metal Formingmentioning

confidence: 99%

“…However, the selection of the proper plasma-nitriding parameters and post-treatment conditions is crucial. 25,35 The presence of a compact g' (Fe 4 N) compound layer may enhance the galling resistance against stainless steel, while a combination of porous e (Fe 2-3 N) and g' compound layer and the use of a non-polished, nitrided surface have a detrimental effect (Figure 3).…”

Section: Cold Sheet-metal Formingmentioning

confidence: 99%

“…Proper selection and preparation of the surface topography, using techniques like polishing, shot-peening and laser surface texturing, can greatly improve the performance and galling resistance of the forming tools, and thus reduce or even eliminate the need for lubrication. 7,25,26 …”

Section: Introductionmentioning

confidence: 99%

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Wear mechanisms and surface engineering of forming tools

Podgornik¹,

Leskovšek²

2015

Mater. Tehnol.

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The manufacturing of parts is faced with ever-increasing demands for higher strength (hardness) and toughness of the work material, as well as higher productivity and environmental concerns. At the same time, the quality requirements are high and will continue to grow in the future. This leads to restrictions in terms of the type and use of lubricants and especially to increased requirements relating to the wear and fatigue resistance of tools. The main focus on improving the wear resistance and tribological properties of forming tools has mainly been on developing tool steels with an improved fracture toughness and then modifying the lubricants for better retention and permeability at the tool/work-piece contact area. Nevertheless, the wear resistance of forming tools can also be successfully improved by surface-engineering techniques. In recent years, hard coatings in particular have shown enormous potential for improving the tribological properties of contact surfaces. This paper reviews the wear mechanisms encountered in forming processes, as well as various surface-engineering techniques designed to improve the wear resistance and the anti-sticking properties of forming tools. The possible benefits and restrictions of different surface-engineering techniques are presented for the example of sheet-metal forming, fine blanking and forging. Keywords: surface engineering, forming, hard coatings, topography, friction, wear Preoblikovalna industrija se spopada z nenehno nara{~ajo~imi zahtevami po vi{ji trdnosti (trdoti) in`ilavosti preoblikovanih materialov, kakor tudi ve~ji produktivnosti in skrbi za okolje. Isto~asno se pove~ujejo zahteve po kvaliteti izdelkov, kjer predvsem kvaliteta povr{ine postaja vedno bolj pomembna. To pomeni omejitve pri uporabi maziv ter seveda ve~je zahteve po obrabni odpornosti in vzdr`ljivosti preoblikovalnih orodij. Do nedavnega je izbolj{evanje obrabne obstojnosti in tribolo{kih lastnosti preoblikovalnih orodij temeljilo predvsem na razvoju bolj`ilavih in~istej{ih orodnih jekel ter modifikaciji maziv z bolj{imi mazalnimi lastnostmi. V zadnjih letih pa tudi na podro~ju preoblikovalnih orodij tehnike in`eniringa povr{in, {e posebej nanos trdih za{~itnih prevlek, omogo~ajo nadaljnje izbolj{anje tribolo{kih lastnosti kontaktnih povr{in. V prispevku so tako predstavljeni obrabni mehanizmi, ki so jim izpostavljena preoblikovalna orodja, kakor tudi razli~ne tehnike in`eniringa povr{ine, namenjene izbolj{anju obrabne obstojnosti in tornih lastnosti preoblikovalnih orodij. Problemi in prednosti uporabe in`eniringa povr{ine so poudarjene na primeru hladnega preoblikovanja plo~evine, {tancanja in kovanja.

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Section: Cold Sheet-metal Formingmentioning

confidence: 99%

Section: Cold Sheet-metal Formingmentioning

confidence: 99%

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Wear mechanisms and surface engineering of forming tools

Podgornik¹,

Leskovšek²

2015

Mater. Tehnol.

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“…Galling failure is described as a form of surface damage arising between sliding solids, distinguished by macroscopic, usually localized, roughening and creation of protrusions above the original surface. The impact of galling failure on production in the forming processes is dramatic, accounting for up to 71% of the cost for die maintenance [1][2] . In recent years, with the high strength steels widely used as lightweight materials in automobiles, there has been great interest in prevention of galling failure through modifying the surface conditions of the tools, including application of coatings, new tool materials [3][4] .…”

Section: Introductionmentioning

confidence: 99%

Galling failure analysis in sheet metal forming process

Hou

2010

J. Shanghai Jiaotong Univ. (Sci.)

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Galling is a known failure mechanism in sheet metal forming operations, and it can lead to fracture of the products and jamming of the tool. The temperature field and normal contact pressure distributions of the tool and the blank were studied with a finite element analysis model under the action of different blank holder force and frictional coefficient. A series of forming tests of the high strength steel were conducted to validate the finite element model. The characteristics of galling failure, the damaged surface of the product and the adhesive wear of the tool, were analyzed during the forming process. The results demonstrate that die corner is the region where temperature and normal contact pressure are high and galling failure initiates. The blank surface passing through the die corner usually has the galling problem. The blank holder force and the tool surface topography have strong effects on the galling behavior in sheet metal forming processes. The methodology using finite element analysis to predict galling failure behavior can be used to perform parametric and material studies on the galling failure.

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“…Thus, fresh and clean titanium should not be in direct contact with the die material during the specific surface treatment. 9) Hutchings et al investigated six different surface treatments for the galling protection of titanium alloys.…”

Section: Effect Of Thermal Oxidation On the Workabilitymentioning

confidence: 99%

Effect of Surface Treatment on the Hot Forming of the High Strength Ti-6Al-4V Fastener

et al. 2009

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The Ti-6Al-4V alloy is a very attractive material for the fastener bolt of an aircraft because of its excellent combination of specific strength and corrosion resistance. However, poor workability and severe galling between work-piece and die material make it difficult to produce. The aim of the present work is to enhance the hot formability of the Ti-6Al-4V bolt. Multiple forgings were simulated using FE code to determine optimum process parameters including workpiece temperature, strain rate, and damage value. Various thermal oxidation treatments were investigated in order to prevent galling and increase the hot-workability. After the oxidation treatment, hot forging was conducted and the microstructure of forged specimens was investigated. Among the various heat treatments, holding at 750 C for 2 h provides the most homogeneous microstructure and a sufficiently low galling phenomenon after forging. Mass-gain versus time curves for isothermal oxidation were obtained in order to analyze the oxidation behavior.

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Improvement in galling performance through surface engineering

Cited by 21 publications

References 12 publications

Wear mechanisms and surface engineering of forming tools

Wear mechanisms and surface engineering of forming tools

Galling failure analysis in sheet metal forming process

Effect of Surface Treatment on the Hot Forming of the High Strength Ti-6Al-4V Fastener

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