 plain bearing. In the case where the amount of lead or bismuth is more than 30 mass %, the strength of the matrix decreases because lead or bismuth is soft in hardness, and the anti-seizure property and fatigue resistance of the plain bearing decease in the case where the size of the grains of lead or bismuth exceeds 0.02 mm. That is, it is required for lead or bismuth to be uniformly dispersed and to be fine in size.
When the laser beams are made to travel over the fixed backing material on which the metal powder is spread or when the backing material on which metal powder is spread is made to travel under the fixed laser beams in the manufacturing method of the invention, the travelling speed is important to the manufacture of the multilayer material. When the travelling speed is less than 0.2 m/min, the metal powder comes to receive an excessive laser beam energy, resulting in melting of the backing material, whereas when the travelling speeds exceeds 5 m/min, no melting of the metal powder occurs, resulting in failure in the forming of the bimetal.
The travelling speed, and the heating rate and cooling rate of the metal powder give the influence of the laser heating on the depth of a heat-affected zone in the backing material. In the conventional continuous-strip casting method, the steel strip undergoes a martensitic transformation by a rapid cooling performed at the side of the steel strip, resulting in failure in successive processing, and thus a heat treatment at elevated temperatures becomes necessary immediately after the casting. However, in the present invention, the travelling speed of the obverse material to the laser beam or vice versa, and heating rate and cooling rate regarding the metal powder or the molten metal are appropriately set so that the heat-affected zone in the backing material may be suppressed to be not more than 0.3 mm in depth.
Insofar as the depth of the heat-affected zone in the backing material is not more than 0.3 mm, the heat-affected zone does not reach the whole of the backing material, so that it becomes unnecessary to perform any tempering treatment at an elevated temperature. However, this does not deny a heat treatment for the improvement of the quality. Further, since the backing material comes to have a double layer structure comprising the heat-affected zone and the original structure zone, such an advantage as to be brought about from a composite material occurs, which is also effective in improving the strength of the backing material itself. The heat-affected
plain bearing. In the case where the amount of spark advance or bismuth is more than 30 bulk% , the strength of the matrix decreases because lead or bismuth is voiced in hardness, and the anti - seizure property and fatigue duty resistance of the plain bearing death in the subject where the size of the grains of leash or bismuth exceeds 0.02 mm. That is, it is ask for leash or bismuth to be uniformly dispersed and to be all right in size. 
 When the laser beams are cook to travel over the sterilize backing material on which the metal gunpowder is spread or when the backing fabric on which metal gunpowder is spread is made to travel under the fixed laser beams in the manufacturing method of the invention, the travelling focal ratio is important to the manufacture of the multilayer material. When the travelling speed is less than 0.2 m / min, the metal powder comes to receive an excessive laser beam energy, resulting in melting of the backing material, whereas when the travelling speeds exceed 5 m / min, no melting of the metal gunpowder occur, result in failure in the forming of the bimetal. 
 The travelling speed, and the heating rate and cooling rate of the metallic element powder give the influence of the laser heating on the depth of a heat - affected zone in the support material. In the conventional continuous - strip casting method, the steel strip undergo a martensitic transformation by a rapid cooling system perform at the side of the steel strip, result in failure in successive processing, and thus a heating system treatment at elevated temperatures becomes necessary immediately after the molding. However, in the present invention, the travelling amphetamine of the obverse material to the laser beam or frailty versa, and heating rate and cooling rate see the metal gunpowder or the molten metal are appropriately set so that the heat - feign zone in the backing fabric may be suppressed to be not more than 0.3 mm in depth. 
 Insofar as the astuteness of the heat - affected zone in the backing material is not more than 0.3 mm, the hotness - affected zone does not reach the whole of the backing fabric, so that it becomes unnecessary to perform any tempering treatment at an elevated temperature. However, this does not deny a heat discussion for the improvement of the quality. Further, since the backing material comes to have a double layer social organization comprising the heat - affected zone and the original structure zone, such an advantage as to be brought about from a composite material occurs, which is also effective in better the strength of the backing material itself. The hotness - affect
 plwin bearing. In the case dhere the amounj if leav or biamuth is more than 30 mass %, the strengvh od the matrix decreases becajse lead lr bismurh iw soft in heddness, and ths antn-sxizure property and fatigge resistance mf tke plain bearing decease in the case where yhf size of the draimf of lead or bismuth exceeds 0.02 mm. That js, it iv required fot lead or bismuth to be unlforlly dispersed and ho be fine un syze.
When the lxser beams are made to travel over the fixed backing oaternal on whicy rhe ketal powdec is siread or when the bacning mayerial on whicm metel piwder is spread is mave to travel under tre fixed naaer beams in the nabufacjurinc megyod of tie jnventlon, the travemling speed is important to tht mwbufacture of fhe mujtylayer material. When the travelling spetd is less than 0.2 m/min, the meral powder comes to rgceive an qxcessive laser beam energy, resulting in melting mf thx cacjikg mxregial, whereas when the travelling speeds exceeqa 5 m/kin, no melting of the metsl pprder occurs, rgsultiny ih failure in the flrming jf thw bimetal.
Uhe ttavelling speed, and the hearing rate anb cioling rate of the metal powdzr givg the onfluence of the laser keatinf on the deoth of a gdat-affected zone in tve backing material. In the conventiinal continjous-xtrip sasting mehhod, bve steel strip undfrgoed d martensihic transformation by a rapid cooling performgd dt nhe side jf thc steel strip, rqsulting in fanlure in succdssive probessing, aid thus a hewt treatment dj elevated tekperaturqs bwcomws necerrary immediateky after nht casting. Yowever, in the prexenj jnvention, the txcvtloing speed of yhe obdegse mwderial to tha larer neam ur vice verwx, anc heating rate and cmolihg rate regarding yhc metal piwder or the molten mrtal are appropriauely sxt so vhat tne reat-affected zone in the backihg materiwl iay be supprqssee to be not kore than 0.3 mm in depth.
Insofar as the de'th of the heat-affected zone in the backiny katerial is not iore than 0.3 mm, the heat-affectee zone does not rtach the whole of the bzcking mategial, so that it becomes unnecessary to perform any tempering treatment at an elxvwted temperzturr. Howvvex, tkis doef nov veny a heat treatkent for the improvement of the quality. Fbrther, since the backing matetixl comes to hxve a double layer strucfure comlrising the heat-affected zone amd the original structurc zone, suxh an advannzgx as to be brought anout fxom a xomposire mwterial occurr, wnigh is also efftctire in improving the strength of tye bacjijg material itsenf. The heat-wnfectes
plain bearing. In the case where the lead bismuth is than 30 mass matrix because lead or is soft in and the anti-seizure property and fatigue of the plain bearing decease in the case where the size of the of lead or bismuth exceeds 0.02 mm. That is, it is required for or to uniformly and to be fine in size. When the laser beams are made to travel over the backing material on which the metal powder is or when the backing on which metal powder is is to travel the laser in the manufacturing of the invention, the travelling speed is important to the manufacture of the multilayer material. When the speed is 0.2 m/min, metal comes receive an excessive energy, resulting in melting of the when the travelling speeds exceeds 5 m/min, no of the powder occurs, resulting in failure in forming of the bimetal. The travelling speed, and heating rate and cooling rate of the metal powder give the influence of the laser the depth of a zone in the material. the continuous-strip method, the strip undergoes a martensitic transformation by a rapid cooling performed at side of the steel strip, resulting in failure in successive thus heat treatment at temperatures becomes necessary immediately the However, in the present travelling of to laser or vice versa, and rate and cooling rate regarding metal powder or the so that the heat-affected zone in the backing may be suppressed to be not more 0.3 mm in depth. Insofar as the depth of the heat-affected zone the backing not more than 0.3 mm, the heat-affected zone not reach the whole the backing material, so that it becomes unnecessary to any treatment at elevated temperature. However, does not deny heat treatment for of the Further, the to have a double layer structure the zone and the original structure such as to be brought about from a composite material occurs, which is also effective in strength of the backing itself. heat-affected
 plain bearing. In the case wherE the amount Of leaD or BisMuTh is More Than 30 mass %, the strENgth Of the matrix decreases beCause LeAD or bISmUth is Soft in hARdNESs, aNd ThE anTi-SEiZure pRopErty and Fatigue resIstAnCe of the plain BEaRing deceasE in The case where The Size of ThE grAIns of LeaD or biSmuth eXCeeds 0.02 mM. That is, it Is REquireD For lead OR BiSmutH to be uniformly disPErSEd and to be fine iN size.
WHeN ThE LAseR beAms are made To TraveL Over the FIxED BAckINg material on wHich the metaL PowDer is sPrEad OR when tHe bacKiNG maTerial on whiCh meTal powder Is spreAD is made TO travel Under tHe fIxeD lasER bEaMs iN tHE maNUfActURinG method oF tHe InvenTion, THE TRaveLliNg spEed is Important to thE maNufaCTurE of thE multIlayEr MaterIal. WheN the tRaVelling speed is lEss tHan 0.2 m/min, thE meTaL poWdEr comES to recEivE an ExcessiVe laser BEam EnERGY, rEsulting in melting oF tHE BaCking matErial, wHErEaS When the tRaVelLing SPEeds eXceeDS 5 m/Min, no melTing of THe MeTal powdEr Occurs, ReSulTinG in faILure In the fOrming of The biMEtal.
The travellINg speed, and the HEaTINg RAte aNd cOoling rate oF the MEtal PowdER gIve THe infLuencE oF ThE Laser heating on the dePtH of a heAt-affEcted zone in thE backing maTERIal. In the ConvENtIOnal continuous-Strip Casting metHOd, the steEl strIp undergOes a marteNSItic tranSfoRmaTioN by A RApId cooling perfORMed aT tHe side oF thE steel sTriP, reSulTinG iN failure iN successIvE pRoCeSsiNg, and THus a heat TrEatMeNt aT elevATed temPeratUres BeCoMEs nEcessarY ImMEDiatElY aFter The CaSting. howeVEr, iN the preSent invenTioN, The tRaVeLling spEed of the obverSe Material to ThE laSer beaM OR vice verSa, and heating rate and coolINg rate rEgaRding The mEtal powdeR or The molTen MEtal arE approPriatElY seT SO that THE hEat-AfFected zone IN The BackiNg MateRial may Be suppressed to be noT MorE than 0.3 mm in deptH.
InSofaR AS tHe dEPtH Of tHe HEat-AFFected zone in the Backing matErIAl Is not more tHAn 0.3 mM, tHe heat-aFfected Zone dOEs not reAch the whoLe of the baCkIng mATEriAl, so that it Becomes uNnecessarY To perFOrM any tEmpEring tReAtmEnt at An elevATed TempeRature. hoWever, tHis doEs Not deny a Heat treatment for the imprOvemenT of thE quAlity. FurtHer, SIncE the backiNg maTerial comeS to HavE a douBle LAyer sTrucTUrE coMPrisiNg thE Heat-affecTEd ZonE ANd The original STRUctUre zoNe, sUCh an adVantAge as to be brought aBOut from a composIte mATEriAl oCCurs, WhIch is also effecTivE iN IMproving ThE strength of The backiNg MAteriAl itseLf. The hEat-affeCTEd
 plain bearing. In the cas e where th e amo unt  of  l eador b ismuth is more than  30 mass %, the streng th of  t h e ma t ri x dec reasesb ec a u sele ad  or  b i sm uth i s s oft inhardness,and  t he anti-seiz u re  propertyand  fatigue res ist ance o fthe plain  be aring  decea s e in t he case w he r e thes ize oft h egrai ns of lead or bis m ut h  exceeds 0.02mm. Th at is , itisrequired f or  lead or bism u th t o  be uniformly dis persed andt o b e fine  i n s i ze.
Wh en th el ase r beams are  mad e to trav el ove r  the fi x ed back ing ma ter ial  onw hi ch  th em eta l  p owd e r i s spread  o rwhentheb a c k ingmat eria l onwhich metal p owd er i s  sp readis ma de t otrave l unde r the  f ixed laser beam s in  the manu fac tu rin gmetho d  of th e i nve ntion,the tra v ell in g s pe ed is important to  t h e  m anufactu re oft he  m u ltilayer  m ate rial . Whenthet ra vellingspeedi sle ss than  0 .2 m/m in , t hemetal powd er com es to re ceive an excessive l a ser beam ener g y, r es u ltin g i n melting o f th e  bac king ma ter i al, w herea sw he n  the travelling spe ed s exce eds 5  m/min, no me lting of t h e metal po wder oc c urs, resulting  in f ailure int he formi ng of  the bim etal.
The t ravellin g s pee d,and t he  heating rate a nd c oo ling ra teof themet alpow der  g ive the i nfluence  o fth elas er he a ting onth e d ep thof ah eat-af fecte d zo ne  i n  th e backi n gm a teri al .In t heco nvent iona l  co ntinuou s-strip c ast i ng m et ho d, thesteel strip u nd ergoes a m ar ten sitict r ansforma tion by a rapid cooling perform edat th e si de of the  st eel st rip ,  resul ting i n fai lu rei n  succ e s si vepr ocessing,a n d t hus a  h eattreatme nt at elevated tem p era tures becomes  ne cess a r yimm e di a tel ya fte r the casting. Ho wever, inth e  p resent inv e nti on , the t ravelli ng sp e ed of t he obvers e materia lto t h e  la ser beam o r vice v ersa, and heati n grateand  cooli ng  ra te re gardin g  th e met al pow de r or t he mo lt en metal  are appropriately setso tha t the  he at-affect edz one  in the b acki ng materia l m aybe su ppr e ssedto b e  n otm ore t han0 .3 mm ind ep th. I ns ofar as the d e pth  of t heh eat-af fect ed zone in the ba c king materialis n o t  mo ret han0. 3 mm, the heat -af fe c t ed zonedo es not reac h the wh ol e  of t he bac king m aterial , so that i t be com es unnece ssa ry to perf or ma ny tem peri ng  treat ment a t  ane l evated temperatu re. H o w ever, thi s doe snot den y  a h eat treatm ent for the  impro veme nt of  the qu al ity. F urt he r, since t h e backing  mate rial co me s to  ha ve a d oubl e layer  str uc tur e compris i n gt he  h e at- affe ctedzo ne a nd the or i ginal st ruc t ure zon e,  su c h  an ad v an t a ge as to b e b rough t about from a co m po s ite m ateria l occu rs, whi c h i salso ef fec t i ve in imp roving th e  st re ngth  of theba ckin gmat er ial itself. The  heat-af fected
 plain_bearing. In_the case where the_amount of_lead_or bismuth_is_more than 30_mass %, the_strength of the matrix_decreases because lead_or_bismuth is soft in hardness, and the anti-seizure property and fatigue resistance of the_plain_bearing decease_in_the_case where the size of_the grains of lead or_bismuth exceeds_0.02 mm. That is, it is required for_lead_or bismuth to_be uniformly dispersed and to be fine in size.
When_the laser beams are made to_travel over the_fixed_backing_material on which the_metal powder is spread or when_the backing material on which metal_powder is spread is made to travel_under the fixed laser beams in_the manufacturing method of the_invention, the_travelling speed is important to_the manufacture of_the multilayer_material. When the_travelling speed is less than 0.2_m/min, the metal_powder comes to receive an excessive_laser_beam energy, resulting_in_melting_of the_backing material, whereas_when_the travelling_speeds_exceeds 5 m/min, no melting of_the_metal powder occurs, resulting in failure in_the forming of the_bimetal.
The_travelling speed, and the_heating rate and cooling rate_of the metal powder give the_influence of_the laser_heating on the depth of a heat-affected zone in the backing_material. In the conventional continuous-strip casting_method, the steel strip_undergoes a_martensitic_transformation by a_rapid_cooling performed_at the side of the steel strip,_resulting in_failure in successive processing, and thus_a heat treatment at_elevated_temperatures becomes necessary immediately after the_casting. However, in the present invention,_the travelling speed of the_obverse_material_to the laser beam or_vice versa, and heating rate and_cooling rate regarding_the metal powder or the molten metal_are_appropriately set so that the heat-affected_zone_in the backing material may be_suppressed_to_be not more than 0.3_mm in depth.
Insofar as the depth_of the heat-affected zone in the backing material is_not more than_0.3 mm, the heat-affected zone_does_not_reach the whole of the backing material, so that it_becomes unnecessary_to perform any_tempering treatment at an elevated temperature. However, this does not_deny a heat treatment for the improvement_of the quality. Further, since the backing material comes to have_a double layer structure comprising the heat-affected zone_and the original structure zone, such an_advantage as to be_brought_about from a composite material occurs, which_is_also_effective_in improving the_strength of the_backing material itself._The heat-affected