How To Test The Transferablty Of An Orgnal Manuscrpt

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1 Fnal Draft of the orgnal manuscrpt: Stener, L.; Bouver, V.; ay, U.; Huber, N.: Smulaton of frcton and wear n DL/steel contacts for dfferent loadng hstores and geometres: Ball-on-plate confguraton and pston cylnder-contacts In: Trbology Internatonal 00 Elsever DOI: 0.06/j.trbont

2 Smulaton of frcton and wear n DL/steel contacts for dfferent loadng hstores and geometres: ball-on-plate confguraton and pston-cylnder-contacts L. Stener a,*, V. Bouver a, U. ay a, N. Huber b,c a obert Bosch GmbH, ostfach 06050, Stuttgart, Germany. b Insttut für Werkstoffphysk und Technologe, TUHH, Eßendorfer Str. 4, 07 Hamburg, Germany. c Insttute of aterals esearch, GKSS esearch entre Geesthacht, ax-lanck-str., 50 Geesthacht, Germany. Abstract DL-coatngs are commonly used n ndustry as a wear protectve layer and as a sold lubrcant for hghly loaded trbologcal contacts. In order to evaluate the wear performance of dfferent DL-coatngs under unlubrcated oscllatng sldng wear condtons and to valdate the relablty of coated components, many wear-tests wth smple model-geometres as well as expensve endurance-tests wth the real applcaton condtons have to be performed. Ths s because the transfer of the wear results to dfferent contact condtons varaton of load, applcaton geometry s not yet possble. In an earler paper a novel unfed dsspated energy model for the ball-on-plate-geometry was developed and ts transferablty to dfferent types of coatngs was verfed. In ths paper the model was appled to dfferent load steps and a pston-cylnder-geometry n order to verfy ts generalty. The analytcal wear calculaton tool - the Global Incremental Wear odel GIW - was revsed by consderng dfferent load steps and by mplementng a new approach for the calculaton of wear n the pston-cylndercontact. Based on the good agreement between the expermental results and both wear and frcton smulatons, the valdty of the unfed wear model regardng ts transferablty to dfferent loadng hstores and geometres was successfully proven. Keywords Wear-modellng, carbon-based coatngs, sldng wear, ball-on-plate-contact, pston-cylndercontact

3 . Introducton Durng the last twenty years, Damond-lke arbon- DL- coatngs have attracted consderable attenton n trbologcal applcatons due to ther characterstc propertes of hgh wear resstance, hgh hardness, low frcton coeffcent, enhanced counterpart protecton and chemcal nertness. Especally n hghly loaded trbologcal contacts, DL has the functon of a wear protectve coatng, as t acts as a sold lubrcant [,, 3]. A relable predcton of the coatng s lfetme and a determnaton of the lmtatons of applcaton represent a great challenge, as they would permt a decrease n the number of endurance tests and consequently lead to cost reductons and faster development. Snce no relable wear models exst for the calculaton of complex DL-contacts, the coatng s performance s currently derved through a sequence of numerous wear tests wth dfferent levels of smplfcaton. They range from expensve endurance tests on the real applcaton to smple oscllatng ball-on-plate experments under accelerated condtons unlubrcated, hgh loads. The smplfed experments allow a rapd classfcaton of the coatngs for a specfc applcaton, but the transfer of these results to the real applcaton geometry s very dffcult. The dervaton of wear models for dfferent materals and contact geometres have been ntensvely studed n the recent years and numerous, manly emprcal wear models have been developed to calculate the wear [4-]. However, most of these exstng wear models are restrcted to the specfc contact condtons used for ther development. They do not provde the possblty of transferrng the model to dfferent geometres or caused by dfferent processng condtons to a varaton of materals, as t s usually the case n ndustral applcatons. Ths also apples to the modellng of DL-contacts [3, 4]. In a prevous work [5], we therefore developed an enhanced unfed wear model, whch was developed and valdated wth the help of experments n a ball-on-plate-geometry. It calculates the wear and frcton behavour of DL-coatngs of dfferent roughness, hardness and Young s modulus as well as the wear behavour of the steel counterpart n an unlubrcated oscllatng sldng test. We acheved ths wth an teratve process ncludng modellng, smulatons and experments. The model was valdated by means of three dfferent types of DL-coatngs wth dfferent degrees of surface roughness.

4 In ths paper, we wll prove that our wear model can be transferred to dfferent loadng hstores and geometres wthout any further adjustments. It enables lfetme predctons of a component based on accelerated model experments and allows the desgner of a component to evaluate the applcablty of a certan coatng for a specfc applcaton. The model s based on the dsspated energy approach [, ] and the assumpton that the ~ m cp dmensonal wear coeffcent k / of a specfc materal m sldng aganst a counterpart cp s D the product of a general materal- and roughness-ndependent dmensonal wear coeffcent k cp m and the rato of the hardnesses H and H of the contactng surfaces. For the calculaton of the wear depth we obtaned the dfferental equaton dh ds m / cp ~ cp * H ~ m = k µ s p s k / D = m D 443 H ~ m / cp k D cp FN µ s, A s real ~ * D where h m/cp s the wear depth of the materal m sldng aganst a counterpart cp, µs the frcton coeffcent and ps the contact pressure. The wear calculaton s then realzed wth the extended analytcal numercal tool named Global Incremental Wear odel GIW [5]. It ntegrates the unfed wear model n dependence of the appled load and sldng velocty based on the present average contact pressure. The average contact pressure s calculated from the global geometry change due to wear and due to the current elastc deformaton n contact [4]. In the extended tool [5], mportant wear nfluencng contact varables descrbng the wear- and frcton-mechansms are mplemented n form of evoluton equatons. They descrbe, n addton to the development of the lnear wear, the surface roughness of the DL-coatng, the oxdaton of the steel-counterpart as well as the graphtsaton of the DLcoatng based on a sngle set of materal parameters charactersng the DL/steel trbo system. The effect of dfferent coatngs s ncluded by easy to access parameters, such as surface roughness, hardness and Young s modulus. The resultng generalty of ths unfed wear model reduces the parameters, whch are responsble for the descrpton of wear, to the ~ dentfcaton of a sngle wear coeffcent k * D. The valdty of ths modellng approach was carefully valdated for dfferent types of DL-coatngs and dfferent degrees of surface roughness [5]. Feldfunkton geändert In ths study, the model s used to predct the frcton and wear behavour for dfferent loadng hstores for the ball-on-plate-geometry and the pston-cylnder-geometry. The predcted wear

5 behavour s compared wth expermental results wth reduced dealsaton and dfferent geometry. Ths represents a further valdaton of the unfed wear model for wear condtons closer to the real applcaton load varaton, component-geometres and proves ts transferablty.. Experments. Expermental setups To prove the generalty of the unfed wear model for a modfed loadng hstory as well as for a modfed geometry we used a standard SV oscllatng sldng wear tester manufactured by Optmol Instruments rüftechnk GmbH, once wth a ball-on-plate geometry, as shown n Fgure, as well as wth a pston-cylnder-geometry, as shown n Fgure... The ball-on-plate-geometry For the ball-on-plate-geometry, a 00r6-steel-ball wth a radus b = mm sldes aganst a flat sample, whch can be coated wth two dfferent types of DL-coatngs A and B. The nvestgated DL-coatngs, dfferng n elastc modulus and hardness, were deposted on flat 00r6-steel samples. The coatng s and the 00r6 steel s mcro-hardness values were measured accordng to EN ISO 4577-:00 and have the followng values: A: 4 Ga, B: 4 Ga, and 00r6: 4 Ga... The pston-cylnder-geometry For the pston-cylnder-geometry, a X90roV8-steel-cylnder wth an nsde radus of ± mm s tested aganst two dfferent types of DL-coatngs A and B on a steel pston wth an outsde radus of ± mm after deposton. The mcrohardness of the cylnder s 4 Ga, the coatngs are the same as for the ball-on-plategeometry.

6 Fgure : Testng devce for oscllatng ball-on-plate experments Fgure : Testng devce for oscllatng pstoncylnder experments.. Expermental test parameters All sldng wear tests are preceded by a runnng-n phase n order to ncrease the reproducblty of the measured wear results. The change of the man testng-parameters force, ampltude and frequency durng the runnng-n phase and durng the subsequent wear test s dsplayed n Fgure 3 respectvely 4. For the ball-on-plate geometry, three dfferent loadng condtons are appled after the runnng-n phase wth a mean load of 40 N. Due to ts hgher wear resstance n comparson to coatng A, the load steps for coatng B last 0 mn longer. The frst type of test starts wth a sequence of three ncreasng load steps of 0 N, 40 N and 60 N, where each step lasts 0 mn for coatng A and 30 mn for coatng B. The second test apples a constant load of 40 N for 60 mn for coatng A and 90 mn for coatng B respectvely, and the thrd test 3 conssts of three decreasng load steps of 60 N, 40 N and 0 N, where agan each step lasts 0 mn for coatng A and 30 mn for coatng B. The frequency and the ampltude are kept constant at 40 Hz and 400 µm, respectvely. The wear of the pston-cylnder-contact s nvestgated at two dfferent constant loads of 50 N and 300 N for duraton of up to 60 h.

7 Fgure 3: Standard test-parameters for the runnng-n phase and the subsequent wear test for the ball-on-plate geometry. After 48m of sldng, the parameters are set to the desred test condtons for the wear tests - 3. Fgure 4: Standard test-parameters for the runnng-n phase and the subsequent wear test for the pston-cylnder geometry. After 4m of sldng, the parameters are set to the desred test condtons for the wear tests and. For the ball-on-plate-test, t s not possble to nterrupt a test n order to measure the wear, so that the wear depth of the coatng s measured only at the end of each ndvdual test. The next test has to start wth a new par of samples. In the case of the pston-cylnder-experment, a contnuaton after measurement was possble. The wear depth was measured by means of cuts of calottes n the centrelne of the wear track. In ths study, we consder only the coatng s wear. For the ball-on-plate-geometry, ths s due to the fact that the man proporton of the counterpart s wear takes place durng the runnng-n phase [5]. Thus, the effect of the dfferent loadng hstores on the counterpart s wear s too small and vanshes n the testng scatter. For the pston-cylnder-geometry, the cylnder s wear s not measurable wth avalable measurement technology. 3 Extenson of the GIW 3. Loadng hstory for ball-on-plate-geometry

8 To model dfferent loadng hstores, the GIW-routne [5] had to be extended to smulate ntervals of dfferent load, dfferent frequency and dfferent endurance as presented n Fg. 3. As the GIW was already extended from [4] to [5] by addng the runnng-n phase wth lnearly ncreasng load at dfferent frequency, the present modfcaton wth addng testng segments at dfferent forces was straght forward and needs no detaled elaboraton. 3. Transfer to the pston-cylnder-geometry The orgnal GIW for ball-on-dsc [6] assumng that only the ball wears was extended n earler works by ncludng the dscs wear [4] and for predctng wear n a twn wheel trbometer [7]. In ths work, the GIW s adapted to the pston-cylnder-geometry n order to evaluate the transferablty of the unfed wear model n accordance to the avalable valdaton experments. The pston-cylnder-geometry s typcal for applcatons of DL n ndustry and represents a more realstc stuaton compared to the ball-on-plate model experment, whch was used to develop the unfed wear model and to dentfy the model parameters. The ntal contact stuaton n the pston-cylnder-geometry represents a Hertzan lne contact, whch allows estmatng the ntal contact area and contact pressure by an analytcal soluton [8]. The maxmum contact pressure pmax along the centrelne of the contact can be calculated accordng to Hertz wth FN pmax =. π b l Here F N s the normal load, l s the contact length, whch corresponds to the length of the cylnder and b s the half wdth of the contact, gven by b = F π l N E *. 3 In Eq. 3 s the outsde radus of the pston, the nsde radus of the cylnder and E * the reduced elastc modulus. The contact wdth a, whch marks the edge of the wear track A wth dh m/cp /ds=0, s approxmated by 0-tmes the half wdth b of the contact, such that the pressure at A s less than 0 percent of the ntal pressure [8] and can be consdered as zero. Due to the wear, both the outer surface of the pston and the nner surface of the cylnder wll rapdly adapt to each other. Ths leads to a change n contact geometry, whch s represented by and. Ths conformaton s mplemented n the GIW-routne as descrbed n the Formatert: Schrftartfarbe: Blau

9 followng subsectons. As the GIW calculates the wear ncrementally n dependence of the sldng cycles, the equatons are formulated approprately. The relevant amount of wear relevant s lmted to the coatng thckness, whch s small compared to the dmensons of the pston and cylnder. Thus we can assume that Eqs. -3 are applcable durng the whole lfetme smulaton. We calculate the new nner radus the cylnder and the new outsde radus and of the pston wth each wear ncrement,.e. of are the rad at the current wear ncrement. For the calculaton loop at step we use and to determne the half wdth b due to Eq. 3 and the contact wdth a = 0b. The adaptaton of and gven, we can calculate p max from Eq. and are descrbed n the followng two subsectons. Once they are Δ h from Eq.. Gelöscht: due to Gelöscht: due to 3.. Adaptaton of the nner radus of the cylnder From the prevous wear ncrement, we assgn and. The nsde of the cylnder s characterzed by a crcle of radus wth centre pont at 0 / 0. As demonstrated n fgure 5 a and b, we select for the followng consderatons two ponts and A -, the frst n the mddle of the contact and the second at the edge of the wear track. We assume that the cylnder s wear of Δ h s fully effectve along the centrelne at the contact pont 0 /. Thus the old pont s dsplaced to the new pont wth the coordnates : 0 / + Δh. Ths mples that the pston wll gradually rub tself nto the cylnder. The new worn poston of the cylnder, respectvely of the crcle s descrbed wth the new cylnder radus and the new centre pont : 0 / y. In order to recalculate both radus and centre pont, we further suppose that the pont A remans n ts poston. Accordng to ythagoras theorem, ts coordnates are determned by the contact wdth of a A A and are gven by : x / y = a A / a. As both A and le on the crcle determned by and, we obtan the followng. x x A x x A + y + y y y = = Ths s an explct solvable system of equatons. Wth the above constrants, the solutons are 4

10 h a h h y + Δ Δ Δ =, 5. y y a + = 6 Fgure 5: Scheme of the conformaton of the pston-cylnder-contact. a Adaptaton of the nsde radus of the cylnder. b Adaptaton of the outsde radus of the pston. 3.. Adaptaton of the outer radus of the pston The adaptaton of the outsde radus of the pston s realzed analogously to the adaptaton of the nsde radus of the cylnder. Agan we descrbe the outsde of the pston by means of a crcle wth central pont at the coordnates 0 0 / and a radus. Addtonally, we select the ponts 0 / : and = / : A A y x A / a a lyng on the crcle. As shown n fgure 5 b, the pont on the centrelne of the contact moves along the negatve y-axs wth h Δ, the edge pont A - =A remans n ts poston. Solvng the resultng system of equatons, we obtan the followng expresson for the y-coordnate y of the new central pont 0 / : y of the outsde of the pston n wear ncrement,, h a h h y Δ Δ Δ = 7 and the new outsde radus of the pston,. y y a + = 8

11 4. Verfcaton of the unfed wear model In ths secton, the transferablty of the unfed wear model wll be valdated by comparng the wear calculatons wth the expermental results for dfferent loadng hstores for a ball-onplate-geometry and for a pston-cylnder-geometry wth dfferent but constant load. As mentoned above, ths s realzed by comparng the wear calculatons - all carred out wth ~ the same constant wear coeffcent k * D - wth the expermental results. 4. Loadng hstory for ball on plate Fgure 6 and 7 demonstrate the calculated and the expermentally measured wear depths h c of coatng A and B n dependence on the sldng dstance s for the above mentoned loadng hstores. For both coatngs we observe a very good agreement between the expermental results and the predcted wear behavours. The effects of the varyng loadng hstory are clearly vsble n the expermental data ponts and the observed phenomena are predcted correctly ncludng the shape of the curves as well as the quanttatve effect. Fgure 6: wear depth of the coatng A n dependence on the sldng dstance for dfferent loadng hstores. Fgure 7: wear depth of the coatng B n dependence on the sldng dstance for dfferent loadng hstores. If we would assume a constant frcton coeffcent µ and contact area A real n equaton, we would expect that the wear depends only on the appled normal load and duraton. Snce all three dfferent loadng hstores have the same mean normal load, ths would lead to an ntersecton of the wear curves at the end of the thrd wear step at pont X. However, Fgure 6 and 7 show that ths s not the case. The results clearly support our approach of usng evoluton equatons, whch allow ntegratng the current condtons for frcton and wear n form of state varables over the whole loadng hstory. Interestngly, the results ndcate that t s an advantage to nduce the hgh loads n the early part of the loadng hstory.

12 As the counterpart wears manly durng the frst few cycles of the runnng-n and as the polshng of the surface roughness manly proceeds durng both the runnng-n and the frst load step [5], the predcted real contact pressure p real at the aspertes can be assumed to be approxmately constant durng the second and the thrd wear step as shown n fgure 8 and 9 for the coatngs A and B respectvely. Gelöscht: prmary Feldfunkton geändert Gelöscht: s Fgure 8: predcted real contact pressure at the aspertes of coatng A n dependence of sldng dstance for dfferent loadng hstores n ball-on-dsc-geometry. Fgure 9: predcted real contact pressure at the aspertes of coatng B n dependence of sldng dstance for dfferent loadng hstores n ball-on-dsc-geometry. Formatert: Zentrert Snce the oxde layer s formed wthn the frst cycles, also the rato of contact hardnesses can also be presumed to be constant. Altogether, ths mples that the load- and roughnessdependent frcton coeffcent s responsble for the advanced ntersecton of the curves, leadng to a lower fnal wear for the type 3 loadng hstory. The comparson between the predcted and the expermentally measured frcton coeffcent s presented n Fgure 0 for coatng A and n Fgure for coatng B. Both are n good agreement. Only for coatng A wth type 3 loadng hstory, the expermental measured frcton coeffcent ncreases at the end at load step 3 whle the predcted behavour remans at a constant low level. omparng the curves wthn Fg. 0 and, the ntally hgh load of 60N evdently accelerates the decrease of the frcton coeffcent n the early stage of the experment. The hgher load ncreases both the wear of the surface aspertes and the contact temperature, leadng to an accelerated transformaton of the DL-coatng. The agreement wth the expermental results verfes the approach of the roughness- and graphtsaton-dependent frcton coeffcent of the unfed wear model, as t has been proposed n [5].

13 Fgure 0: omparson of predcted and measured frcton coeffcent µ as a functon of sldng dstance for coatng A and dfferent loadng hstores. a ncreasng load steps, 0N-40N-60 N, b decreasng load steps, 60N-40N-0 N Fgure : omparson of predcted and measured frcton coeffcent µ as a functon of sldng dstance for coatng B and dfferent loadng hstores. a ncreasng load steps, 0N-40N-60 N, b decreasng load steps, 60N-40N-0N 4. ston-cylnder-geometry In order to prove the transferablty of the unfed wear model, we use the extended GIW as descrbed n Sect. 3. to apply the wear model to the pston-cylnder geometry. The GIW s predctons and the expermentally measured wear depths for the coatngs A and B pston are presented n Fgure and 3. For coatng A, the wear behavour has been nvestgated for 50N and for 300N. For coatng B, only data for 300N are gven, as the hgh wear resstance would lead to extremely long test duratons at the lower load. We fnd a remarkable good agreement between the expermental results and the smulated wear predcton. Only n the case of coatng A tested at 50N, the expermental results are below the predcton for very large sldng dstances of more than 6000 m. It can not be excluded that naccuraces durng the reassembly after each wear measurement can cause errors n the experments, whch sum up and lead to lower amounts of wear partcularly under small load. Despte ths uncertanty these results ncely confrm the geometry-ndependency of the unfed wear model and ts potental for precse wear and lfetme predctons under condtons as they are present n ndustral applcatons.

14 Fgure : wear depth of coatng A n dependence on the sldng dstance for 50N and 300N n pston-cylnder-geometry. Fgure 3: wear depth of coatng B n dependence on the sldng dstance at 300N n pston-cylndergeometry. Gelöscht: Feldfunkton geändert Fgure 4 demonstrates the real contact pressure p real n dependence of the sldng dstance s for both coatngs A and B n the pston-cylnder-geometry. We can see that after the adaptaton of the contactng surfaces and after the polshng of the surface roughness the real contact pressure s stablzed at around 0 N/mm. Ths pressure level s between one and two orders of magntude smaller compared to the pressure n the accelerated ball-on-plate model experment see Fgure 8 and 9. The fact that the pressure range used for the model development does not drop near to the level present n the pston-cylnder-geometry underlnes the mportance of the quanttatvely correct predctons presented n Fgs. and 3. Hence, the valdty of the unfed wear model for both geometres s a further demonstraton of the generalty of the unfed wear model. Gelöscht: at the aspertes Feldfunkton geändert Gelöscht: In comparson, t Gelöscht: stablzed Gelöscht: then Gelöscht: the real contact Gelöscht: of Gelöscht: -geometry Gelöscht:, whch s shown n Gelöscht: for the coatngs A and B respectvely Gelöscht: T Gelöscht:, although the real contact pressures have dfferent magntudes, Formatert: Schrftart: Standard Tmes New oman, Ncht Fett Formatert: Englsch Großbrtannen Fgure 4: predcted real contact pressure at the aspertes of coatng A 50N / 300N and B 300N n dependence of sldng dstance n pston-cylnder-geometry. 5. onclusons

15 In ths study we successfully valdated a novel unfed model, whch allows predcng the behavour of frcton and wear n DL/steel contacts for varous loadng hstores and geometrcal confguratons. In the case of a ball-on-plate-geometry dfferent types of loadng hstores were appled rangng from steps wth ncreasng, constant, and decreasng load. It was shown that the GIW mplementaton of the model accurately predcts both frcton and wear behavour for the dfferent loadng hstores. oreover, we could show that hgher loads n the ntal stages accelerate the generaton of graphte, leadng to an mproved lubrcaton and lfetme of the component. The transferablty of the wear model to other geometres was shown usng a pston-cylndergeometry wth constant load after runnng-n. The predctons for the dfferent geometry were performed by the extenson of the GIW for the new geometry only and wthout any adaptaton of the wear model or ts parameters tself. The agreement between the expermental results and the predctons obtaned from the GIW valdates the unfed frcton and wear model and underlnes the mportance of consderng the whole evoluton of the mportant physcal phenomena, such as surface roughness, graphtsaton, and oxdaton of the counterpart throughout the lfetme of a component. Formatert: Schrftartfarbe: Automatsch Formatert: Schrftartfarbe: Automatsch 6. Acknowledgement Ths work has been fnancally supported by obert Bosch GmbH and the German esearch Foundaton DFG under the sub-project T3 wthn the scope of the collaboratve research center, SFB 499 Desgn, producton and qualty assurance of molded mcroparts constructed from metals and ceramcs. We wsh to express our thanks to the obert Bosch GmbH for suggestng the problem and offerng us the opportunty to work on t. 7. eferences.. Donnet, A. Erdemr, Trbology of Damond-Lke arbon Flms, Sprnger, 008, p.6.. H. onkanen, Trbologcal propertes of hydrogenated and hydrogen-free damond-lke carbon coatngs, Helsnk Unversty of Technology, Helsnk, Fnland 00, p.38.

16 3... O Treutler, Industral use of plasma-deposted coatngs for components of automotve fuel njecton systems, Surface and oatng Technology Holm, Electrc contacts, Almqvst and Wksells Boktryxker AB, Uppsala J. F.Archard, ontact and ubbng of Flat Surfaces, Journal of Appled hyscs H.. eng, Wear odelng: Evaluaton and ategorzaton of Wear odels, hd Thess, Unversty of chgan, USA H.. eng, K.. Ludema, Wear odels and redctve Equatons: Ther Form and ontent, Wear J. F. olnary,. Ortz, O. adovtzzky, E. A. epetto, Fnte Elemente odelng of Dry Sldng Wear n etals, Engg. omput T. F. J. Qunn, Oxdatonal Wear, Wear A. D. Sarkar, Frcton and Wear, Academc ress, London 980.,.. atveesky, The rtcal Temperature of Ol wth ont and Lne ontact achnes, Trans. ASE T. Lskewcz, S. Fouvry, Development of a frcton energy capacty approach to predct the surface coatng endurance under complex oscllatng sldng condtons, Trbology nternatonal J. Jang,. D. Arnell, On the runnng-n behavour of damond-lke carbon coatngs under the ball-on-dsk contact geometry, Wear V. Hegadekatte, N. Huber, O. Kraft, odelng and smulaton of wear n a pn on dsc trbometer, Trbology Letters Btte DG-aper enfügen und eferenzen nach hnten updaten! 6. L. Stener, V. Bouver, U. ay, V. Hegadekatte, N. Huber, odellng of unlubrcated oscllatng sldng wear of DL-coatngs consderng surface topography, oxdaton and graphtsaton, submtted for publcaton, V. Hegadekatte, N. Huber, O. Kraft: Development of a Smulaton Tool for Wear n crosystems; n Baltes, Brand, Fedder, Herold, Korvnk, Tabata Eds.: Advanced cro and Nanosystems, Vol. 4; D. Löhe, J. Hausselt Volume Eds.: croengneerng of etals and eramcs, art II: Specal eplcaton Technques, Automaton and ropertes; Wley VH, Wenhem, pp , 005. Formatert: Hervorheben Formatert: Nummererung und Aufzählungszechen Formatert: Hervorheben Formatert: Nummererung und Aufzählungszechen

17 8. V. Hegadekatte, S. Kurzenhäuser, N. Huber, O. Kraft: A predctve modelng scheme for wear n pn-on-dsc and twn-dsc trbometers, Trbology Internatonal J. E. Shgley,.. schke, Standard Handbook of achne Desgn, Kngsport ress. 986