Ndemanga: Kuti muwonjezere magwiridwe antchito a kavalidwe laser wamba Ni + TiB2 zokutira zokonzedwa pa Ti6Al4V pamwamba, chikoka cha ufa chiŵerengero pa microstructure ndi makina katundu amaphunzira. Chophimba cha laser chimapangidwa makamaka ndi TiB, TiB2, α-Ti, β-Ti, NiTi alloy solid solution ndi TiO2. Chophimbacho chimapangidwa makamaka ndi gawo lakuda elliptic, gawo lotalikirapo ngati singano ndi gawo lozungulira la cell crystal. Gawo lakuda lozungulira, gawo ngati singano ndi gawo lozungulira la galasi la cell ndi TiB2, TiB, NiTi, motsatana. Pamene kuchuluka kwa TiB2 kumawonjezeka, zomwe zili mu TiB zimawonjezeka, tinthu tating'onoting'ono ta TiB timakhala tambirimbiri. Kulimba kwapang'onopang'ono kwapang'onopang'ono kumafika 920. 8 HV1. 0, yomwe ili pafupifupi 3 nthawi ya Ti6Al4V aloyi, kuchuluka kolimba kwa microhardness kumathandizira kukana kukana kwa zokutira zokutira. Kuphulika kwa brittle kumakhala koopsa kwambiri ndi kuchuluka kwa katundu, ndipo zokutira zophatikizika sizoyenera kunyamula katundu wambiri.
Keywords: laser cladding; Ni + TiB2 zokutira zophatikizika; Ti6Al4V; kuvala katundu wotsutsa

1. Introduction

Ma aloyi a Titaniyamu ali ndi zinthu zabwino kwambiri monga mphamvu zambiri, kachulukidwe kakang'ono komanso kukana dzimbiri, ndipo nthawi zambiri amagwiritsidwa ntchito muzamlengalenga, uinjiniya wam'madzi, kupanga magalimoto ndi magawo ena [1]. Komabe, kuuma kochepa komanso kusamva bwino kwa ma aloyi a titaniyamu kumachepetsa kugwiritsa ntchito kwawo kwakukulu. Muukadaulo wosinthira pamwamba, kuyika kwa laser kokhala ndi mphamvu zambiri, madera ang'onoang'ono omwe amakhudzidwa ndi kutentha komanso kulumikizana kolimba kwazitsulo nthawi zonse kumakopa chidwi kwambiri [2].

Machitidwe osiyanasiyana azinthu adalowetsedwa mu laser cladding ya titaniyamu alloys, yomwe gulu lazinthu zophatikizika ndi njira yotchuka komanso yothandiza kwambiri [3]. Muzinthu zophatikizika, gawo lolimbitsa la TiB2 limagwiritsidwa ntchito ngati njira yotheka yolimbikitsira kuuma komanso kukana kuvala. Qi K. et al. [1] adakonzekera TiB2 / zitsulo zophatikizika zachitsulo pa Ti6Al4V aloyi ndi laser cladding Fe, Co, Cr, B ndi C ufa wosakanikirana, ndipo adaphunzira momwe maginito amagwirira ntchito pamakina ndi kuvala kwa zokutira. Lin YH et al. [4] adagwiritsa ntchito ufa wa TiB2 wangwiro kukonza zokutira za TiB2/TiB pa titaniyamu alloy. Kulimba kwapang'onopang'ono kunawonetsa kutsika kwapang'onopang'ono, koma kulimba kwa fracture kunawonetsa kukwera kwa gradient. Kumar S. et al. [5] adaphunzira kusakaniza kwa ufa wa Ti6Al4V, CBN ndi TiO2 laser cladding coating, ndipo adapeza zinthu zosiyanasiyana monga singano, ndodo yooneka ngati cylindrical komanso yooneka ngati dendrite yayitali. Zida zophatikizika zachitsulo (TiN, TiAlN, AlN ndi TiB2) za nitride ndi boride zidagwiritsidwa ntchito ngati gawo lalikulu la zokutira kuti zithandizire kulimba komanso kukana kuvala.

Nickel kapena nickel-based alloy ndi matrix abwino okhala ndi kukhazikika kwamapangidwe, kukana kutentha kwambiri, kukana dzimbiri, mphamvu yayikulu komanso kunyowa kwabwino. Laser cladding tinthu analimbitsa gulu ❖ kuyanika linakonzedwa mwachindunji kuwonjezera kulimbikitsa wothandizila kapena zinthu zokhudzana ndi wokometsedwa aloyi ufa, ndi laser cladding ❖ kuyanika ndi magawo osachepera awiri ndi katundu osiyana makina adzakhala kufunika kufunika padziko kulimbitsa m'tsogolo [6]. Xu SY ndi al. [7] anakonza TiC/Ni60 ❖ kuyanika gulu pamwamba pa Ti6Al4V aloyi aloyi ndi laser cladding. Yu XL et al. [2] anakonza nickel-titanium carbide composites pa 20 zitsulo gawo lapansi ndi laser cladding. Kuchuluka kwa TiC particles mu gulu la Ni / 40TiC kunalepheretsa kukula kwa makristasi a nickel, zomwe zinapangitsa kuti microstructure yabwino kwambiri ya gulu la Ni / 40TiC. Kulimba kwapang'onopang'ono kwa kaphatikizidwe ka Ni/40TiC kunali pafupifupi 851HV, ndipo kugundana kwapakati kunali 0.43. Wang Q. et al. [8] adaphunzira za microstructure ndi katundu wa Ni-based gradient composite zokutira. Zovalazo zinali ndi Ni matrix, WC ndi ma carbide angapo komanso magawo olimba. Kulimba kwapang'onopang'ono kunafika 1053.5HV0.2, ndipo kugundana kocheperako komanso kutayika kwa mavalidwe kunali kotsika poyerekeza ndi chitsulo cha Q345.

Pofuna kuphunzira microstructure ndi kuvala kukana kwa Ti6Al4V aloyi, Ni ndi TiB2 ufa wosakaniza anasankhidwa kukonzekera Ti6Al4V aloyi laser cladding zigawo.

2 Zida zoyesera ndi njira
2. 1 Zida zoyesera
A 100mm × 100mm × 10mm Ti6Al4V aloyi mbale inasankhidwa kukhala gawo lapansi, ndipo kapangidwe kake ka mankhwala ndi makina ake akuwonetsedwa mu Table 1 ndi Table 2, motsatana. Popeza ufa wa Ni ukhoza kupititsa patsogolo kugawa kwa gwero la kutentha ndikuyika kutentha panthawi ya laser cladding, ufa wa Ni ufa ndi TiB2 ufa adasankhidwa kuti akonze zokutira ndi TiB2 monga gawo lolimbikitsa. Metallographic morphology ya Ni powder ndi TiB2 powder ikuwonetsedwa mu Chithunzi 1.

2. 2 Njira zoyesera
Pofuna kuti ufa ndi m'munsi mbale zomangika mwamphamvu, mawotchi akupera makina ntchito kuchotsa okusayidi pamwamba wosanjikiza aloyi mbale titaniyamu, ndi 5% HF + 15% HNO3 asidi njira ntchito kuchotsa madontho mafuta. A YSL-3000 mosalekeza CHIKWANGWANI laser ntchito kupereka laser mosalekeza, ndi mbale Ti6Al4V ndi ufa preset anaikidwa 200mm × 200mm × 50mm pulasitiki bokosi, ndi mpweya argon mosalekeza jekeseni mu bokosi pulasitiki. Pa laser cladding ndondomeko, malo awiri ndi 1.8 mm ndi jambulani liwiro ndi 7 mm/s. Pamene chiŵerengero cha Ni + TiB2 ndi 40%, magawo a ufa wa laser ndi 700W, 900W ndi 1100W motsatira, ndipo zotsatira za ufa wa laser pa microstructure ndi katundu wamakina amaphunzira; pamene misa ya ufa wa laser ndi 900W, chiwerengero cha ufa ndi Ni + 20% TiB2, Ni + 30% TiB2, Ni + 40% TiB2 motsatira, ndipo zotsatira za chiŵerengero cha ufa pa misa ya ufa wa laser zimaphunziridwa. Zitsanzo zokhala ndi laser cladding wosanjikiza zimatha kulembedwa S-1 (P = 700W), S-2 (P = 900W), S-3 (P = 1100W), S-4 (R = Ni + 30% TiB2), S-5 (R = Ni + 40% TiB2).

Zitsanzo za X-ray diffractometer (XＲD), zowunikira ma electron maikulosikopu (SEM) ndi zoyeserera zoyeserera zidakonzedwa ndi kudula kwamagetsi amagetsi, ndipo zitsanzozo zidatsitsidwa mwamakina, zopukutidwa mwamakina ndi kuonongeka ndi 5% HF + 15% HNO3 acid solution. Kupanga kwa gawo la laser cladding wosanjikiza kumadziwika ndi Brooker D8-advance micro-area X-ray diffractometer (XＲD), ndipo mawonekedwe ang'onoang'ono a laser cladding wosanjikiza adawonedwa ndi ma microscope (OM) ndi makina owonera ma electron (SEM). The HV-5 Vickers hardness tester anaphunziridwa kuyeza kuuma motsatira kuya kwa pamwamba kwa laser cladding layer. HＲS-2M yothamanga kwambiri yobwerezabwereza ndikuyesa kuvala idasankhidwa kuti iyesedwe kukangana ndi kuvala. Zothandizira zokangana zinali Si3N2 ceramic akupera mpira ndi awiri a 4mm. Kukangana ndi kuvala magawo anali kubwereza liwiro la 200r/mphindi ndi ma radial katundu wa 20/40/60N.

3 Zotsatira ndi zokambirana
3.1 XRD gawo kapangidwe
Kupanga kwa gawo la XRD la zitsanzo zisanu kukuwonetsedwa mu Chithunzi 2. Chitsanzo chilichonse chili ndi TiN pang'ono m'mapangidwe ake a mankhwala, chifukwa chake ma atomu a N amalowa mu laser cladding wosanjikiza kuti apange nitriding reaction. Pakuyenda kwa dziwe losungunuka, madzi ochepa a vanadium amasungunuka mu titanium alloy matrix material, ndipo pochita izi, gawo la α limasintha kukhala gawo la β, kotero β-Ti ikuwonekera pa Chithunzi 2. TiB2 ili ndi kusungunuka-mvula. khalidwe pa laser cladding ndondomeko. TiB2 yocheperako imatha kusungunuka kwathunthu, ndipo TiB2 ina imatha kuphatikiza ndi Ti kupanga TiB, ndipo TiB2 yotsalayo imatha kukonzanso. Ti amatha kuchitapo kanthu ndi Ni kuti apange NiTi, Ni3Ti ndi NiTi2, koma Ti ndi Ni ali ndi mphamvu yofananira yamankhwala, zomwe zimapangitsa kuti zikhale zosavuta kupanga chokhazikika chokhazikika chachitsulo cha NiTi, ndipo ma atomu a Ti amakhala ndi kufalikira kwamphamvu, motero Ti ndi Ni. ikani kupanga NiTi yokha［9］. Monga momwe tikuonera pa Chithunzi 2, laser cladding layer imapangidwa makamaka ndi TiB, TiB2, α-Ti, NiTi alloy solid solution, TiO2, etc., ndipo zotsatira za XRD zimasonyezanso pang'ono β-Ti.

Malinga ndi mphamvu yaulere ya Gibbs, machitidwe atatu amatha kuchitika: onani (1), (2), ndi (3) pachithunzichi. Panthawi ya laser cladding process, ma atomu a Ni ndi B amatha kuchitapo kanthu ndi ma atomu a Ti kuti apange TiB2, NiTi, ndi TiB. Wapakati Gibbs mphamvu yaulere ΔG2 <ΔG1 <ΔG3, kotero dongosolo la mapangidwe azinthu ndi TiB> NiTi> TiB2.

Pamene gawo la TiB2 ufa likuwonjezeka kufika 30%, thermochemical reaction formula (2) imapita kumanja. Gawo la TiB mu gawo la laser cladding limawonjezeka ndipo gawo la Ti limachepa. Pamene gawo la ufa wa TiB2 likupitirirabe mpaka 40%, zomwe zili mu magawo a TiB ndi TiB2 zimawonjezeka kwambiri. Kuphatikiza apo, Ni ndi Ti ali ndi mgwirizano wamphamvu ndipo pang'onopang'ono amapanga NiTi metallization. Chifukwa chake, zinthu zazikulu zomaliza za Ni + 40% TiB2 laser cladding wosanjikiza ndi NiTi, TiO2, TiB, TiB2 ndi Ti.

3.2 Microstructure
Mapangidwe a SEM a Ni + 20% TiB2 laser cladding wosanjikiza akuwonetsedwa mu Chithunzi 3. Chophimbacho chimapangidwa makamaka ndi gawo lakuda la elliptical, gawo la singano ndi gawo lozungulira la ma cell. Pafupifupi awiri a gawo laling'ono lomwe limagawidwa kwambiri ndi 0.5 ~ 3.0μm. Popeza nambala ya atomiki ya B element ndi 5, wowerengera mphamvu wamba sangayese molondola zomwe zili muzinthu zomwe zili ndi nambala ya atomiki zosakwana 10. Electron probe X-ray microanalysis (EPMA) imagwiritsidwa ntchito kuyeza kugawa ndi zomwe zili mu chinthu chilichonse mu [10, 11]. Zotsatira za EPMA m'malo osiyanasiyana mu Chithunzi 3 zikuwonetsedwa mu Gulu 3.

Zitha kuwoneka kuchokera ku Table 3 kuti mankhwala omwe amapangidwa ndi nsalu zotchinga amapangidwa makamaka ndi zinthu za Ti, B, Ni, ndipo zimakhala ndi zinthu zochepa za Al ndi V. Zomwe zili muzinthu za Ti ndi Ni zomwe zili pamalo a ndizofanana, palibe B, ndipo yankho lolimba la NiTi lingakhalepo. Zinthu zazikulu zomwe zili pamalo b ndi Ti ndi B, ndipo zomwe zili muzinthu zonsezi zimaposa 40%. Zitha kunenedwa kuti gawo ngati singano pamalo b ndi TiB.

Malinga ndi lamulo la Gibbs la thermodynamic, BB bond energy> B-Ti bond energy> Ti-Ti bond energy [12], zomwe zimapangitsa kukula kwa TiB mumayendedwe ake aatali mwachangu komanso mwachangu kuposa momwe kukula kumayenderana ndi kutalika kwake. zomwe zimapangitsa gawo la singano kukhala losavuta kuwonekera. Zomwe zili mu B element pa position c ndizowirikiza kawiri za Ti element. Mawonekedwe a XRD pachithunzi 2 akuwonetsa kuti kuchuluka kwa nsonga ya diffraction ya TiB2 ndikokwera kwambiri. Gawo lakuda la elliptical pa malo c ndiloyenera kukhala TiB2.

SEM microstructure ya laser cladding layers yokhala ndi ma ratios osiyanasiyana a ufa ikuwonetsedwa mu Chithunzi 4. Zitha kuwoneka kuti pamene zowonjezera za TiB2 ndizochepa, zomwe zili mu TiB muzitsulo zowonongeka zimachepa ndipo kugawa kwake kumabalalikanso kwambiri. Zowonjezera za TiB2 zikawonjezeka, zomwe zili mu TiB zimawonjezeka, tinthu tating'ono ta TiB timakhala tambirimbiri, ndipo kugawa kumabalalika. Chodabwitsa ichi chimayamba chifukwa cha kuchuluka kwa chinthu B chomwe chimalimbikitsa zomwe zimachitika pakati pa B ndi Ti element.

Kuti muphunzire mawonekedwe a zokutira, mawonekedwe a SEM apamwamba, apakati ndi pansi pa zokutira akuwonetsedwa pazithunzi 5.

Kusinthika kwa mawonekedwe a cladding wosanjikiza ndi kuya kwa gradient ndikowonekera kwambiri. Chiwerengero chachikulu cha magawo awiri a particles amapangidwa mu situ pamwamba pa zokutira, zambiri zomwe zimaphwanyidwa bwino, ndipo pali zochepa za singano zooneka ngati singano. Nthawi yomweyo, TiB ndi TiB2 tinthu tating'onoting'ono tolimbitsa thupi titha kuteteza kutentha kwambiri pamwamba pa dziwe losungunuka. Pambuyo pa kusungunuka ndi kuwonongeka, njere zomwe zili muzitsulo zotchinga zimakula mopanda molunjika ndikukhalanso nucleate. Kukula kwa gawo latsopano pambuyo pa nucleation ndi yaying'ono, zomwe zimapangitsa kuti magawowa ayeretsedwe [13]. Pakatikati mwa zokutira zimatha kukhudzidwa ndi kusinthasintha kwa kutentha kuchokera pamwamba mpaka pansi, ndipo zinthu zambiri zimakhazikika pakati, kotero EPMA silingazindikire zinthu za boron, ndipo pamwamba pa ❖ kuyanika kumapangidwa ndi zigawo zakuda zooneka ngati petal. , zigawo zakuda zooneka ngati singano ndi magawo oyera a herringbone.

Monga tawonetsera pa Chithunzi 6, zotsatira za kuyang'ana kwa ndege za microstructure zimasonyeza kuti pali dongosolo lolemera la eutectic. Gawo lakuda lokhala ngati petal lingakhale gawo la TiB/TiB2/TiNiB eutectic, gawo loyera la herringbone ndi NiTi, ndipo magawo enawo ndi ochokera ku kusintha kwa titaniyamu martensitic. BES microstructure pakati pa 20% TiB2 laser cladding zokutira ikuwonetsedwa pa Chithunzi 7, ndi magawo amitundu yosiyanasiyana, yoyera yowala, yakuda ndi imvi yakuda. Chowala kwambiri ndi NiTi intermetallic compound, chakuda ndi titaniyamu-boron yosakanikirana, ndipo imvi yakuda ndi gawo losakanikirana la martensitic titaniyamu ndi titaniyamu oxide. Gawo la herringbone pansi pa zokutira za laser limakula pang'onopang'ono, gawo la mdima wandiweyani limayamba kuwonjezeka, ndipo gawo lakuda lokhala ngati petal ndi gawo lakuda ngati singano limachepetsedwa kwambiri.

3.3 Microhardness
Malinga ndi mayeso a microhardness, kuuma kwa Ti6Al4V alloy ndi 349.2HV1.0. Kugawidwa kwa microhardness kwa zigawo za laser cladding zokonzedwa ndi zosiyana za ufa mozama mozama zikuwonetsedwa mu Chithunzi 8. Zingawonekere kuti microhardness ya laser cladding layers ndi zosiyana za ufa ndizopamwamba kuposa za Ti6Al4V alloy. Ndi kuwonjezeka kwa chiŵerengero cha ufa wa TiB2, microhardness imakula pang'onopang'ono. Pamene chiŵerengero cha ufa wa TiB2 ndi 40%, microhardness yapamwamba kwambiri ya cladding wosanjikiza imafika 920.8HV1.0, yomwe ili pafupifupi 3 nthawi ya Ti6Al4V alloy.

Ndi kuwonjezeka kwa kuya kwa laser cladding wosanjikiza mu osiyanasiyana osiyanasiyana, ndi microhardness wosanjikiza akusonyeza chizolowezi kutsika mofulumira, ndi mtanda gawo wosanjikiza pamwamba kumangirira pamwamba pa gawo lapansi ndi zokutira zimasonyeza kusinthasintha chodabwitsa microhardness. Chigawo chamtanda chokhala ndi kuya kwa 0.7 mpaka 0.8 mm chili m'dera lomwe likukhudzidwa ndi kutentha. Kulimba kwapang'onopang'ono kwa derali ndi pafupifupi 400HV1.0, ndipo kukwera kwa microhardness kumakhala pang'onopang'ono. The microhardness wa mtanda gawo wosanjikiza akuya 0.7 kuti 0.8 mm ndi mkulu chifukwa cholimba TiB2 njere mu laser cladding wosanjikiza ali ndi mphamvu kukana, ndi laser cladding ndondomeko akhoza kulimbikitsa mapangidwe TiB zabwino ndi kuteteza mbewu. malire a dislocation slip, potero kumapangitsa kuti microhardness ya laser cladding layer yokonzedwa ndi laser cladding process [14].

Mothandizidwa ndi kutuluka kwa dziwe losungunuka, pamwamba pa TiB2 imayamba kufalikira, ndipo padzakhala TiB2 yotsalira pakati pazitsulo zotchinga, koma ndendeyo siidzakhala yokwera kwambiri, ndipo microstructure [15] idzachepanso pang'ono. . Mphepete mwa pansi pawotchinga ndi malo omwe amakhudzidwa ndi kutentha. Zinthu zambiri za Ti zimayandama pambuyo pa kusungunuka, zomwe zimapangitsa kusungunuka kwakukulu kwa zinthu za makolo ku dziwe losungunuka, popanda gawo lokwanira lolimbitsa, ndipo malo omwe amakhudzidwa ndi kutentha amakhala ndi microhardness yotsika kwambiri [16]. Zotsatira zikuwonetsa kuti kuwonjezera kwa ufa wa TiB2 kumathandizira kwambiri kuuma kwa gawo la cladding.

3.4 Kukana kuvala
Kuvala kwa laser cladding wosanjikiza ndi ufa womwewo umasiyana ndi katundu monga momwe tawonetsera pa Chithunzi 9. Mitengo yovala ya Ti6Al4V ndi zigawo za laser cladding zimawonjezeka ndi kuwonjezeka kwa katundu, ndipo kuvala kwa zigawo za laser cladding ndi zochepa kwambiri kuposa ya Ti6Al4V substrate materials, kusonyeza kuti kukana kuvala kwa cladding layers ndikwabwino kwambiri. Kuvala kwa zigawo za cladding kumagwirizana kwambiri ndi gawo lolimba. Pamene chiŵerengero cha ufa wa TiB2 chikuwonjezeka kuchokera ku 20% mpaka 30%, gawo lolimba la TiB likuwonjezeka ndipo kuchuluka kwa kuvala kumachepa; pamene chiŵerengero cha ufa wa TiB2 chikuwonjezeka kuchokera ku 30% kufika ku 40%, gawo lolimba la TiB likuwonjezeka, ndipo TiB2 ikuwoneka, zomwe zimapangitsa kuti kuvala kocheperako kumakhala 1.5 × 10-4 mm3 / s.

SEM kuvala morphology ya Ti6Al4V pansi pa katundu wosiyana ikuwonetsedwa mu Chithunzi 10. Monga momwe tawonera pa Chithunzi 10a, titaniyamu alloy imapanga zinyalala zochepa kwambiri zovala pansi pa katundu wa 20 N, ndipo malo ovala amakhala osasinthasintha, opindika, ndi diamondi- mawonekedwe (onani gawo A pachithunzi 10a), kusonyeza kuti gawo laling'ono la Ti6Al4V lawonongeka kwambiri panthawiyi. mayendedwe obwerezabwereza. Pamene katundu akuwonjezeka kufika ku 40N, kuya kwa gully kumawonjezeka (onani dera B mu Chithunzi 10b), tinthu tating'onoting'ono timawonjezeka mofulumira, ndipo kuvala ndi kupatuka kumachitika panthawi yovala gawo lapansi, kotero kuvala kwa abrasive ndi kuvala zomatira ndizoopsa kwambiri. Katunduyo akakhala 60N, maenje ena akulu amapangidwa pamalo ovala (onani malo C pa chithunzi 10c), ndipo tinthu ta abrasive timadziunjikira pazikanda (onani gawo D mu chithunzi 10c). Chifukwa chake, kuchulukirako kumathandizira kutulutsa kwa titaniyamu aloyi panthawi yakusamvana ndi kuvala, ndipo kukangana ndi kuvala kwa titaniyamu aloyi kumakhala koyipa kwambiri. Li JN et al. [17] ndi Weng F. et al. [18] adapezanso zovala zofananira za titaniyamu.

Wosanjikiza wa Ni + 40% wa TiB2 ali ndi kulimba kwapang'onopang'ono kwambiri komanso kukana kovala bwino kwambiri. Choncho, Ni + 40% TiB2 cladding wosanjikiza pa titaniyamu aloyi pamwamba anasankhidwa kuphunzira kavalidwe limagwirira wa laser cladding wosanjikiza. The SEM kuvala morphology wa laser cladding wosanjikiza pansi pa katundu wosiyanasiyana akuwonetsedwa mu Chithunzi 11. The microhardness ya laser cladding wosanjikiza bwino kwambiri, kotero kuvala ntchito ya cladding wosanjikiza bwino kwambiri kuposa aloyi titaniyamu. Monga tikuonera pa Chithunzi 11a, chiwerengero cha abrasive particles chachepetsedwa kwambiri ndipo kukula kwake kwakhala kochepa kwambiri (onani dera A mu Chithunzi 11a). Izi ndichifukwa cha kuvala kwa magawo olimba a NiB, TiB2 ndi TiO2 [5]. Zina zogundika zimawonekera pansanjika zomwe zidatha (onani gawo B pazithunzi 11b). Chojambulacho chikhoza kukhala tinthu tating'onoting'ono tolimba. Tchipisi tating'onoting'ono tachitsulo timakhala ndi mizere chifukwa cha mphamvu yake yonyamula katundu wambiri, kupewa kupanga ma grooves ndi zokopa. Pamene katundu akuwonjezeka kufika 40 N, lamellar spalling ndi zotheka kuchitika, abrasive fumbi la Ni + 40% TiB2 cladding wosanjikiza amakula kwambiri, ma micropores amawoneka pamwamba ovala (onani dera C mu Chithunzi 11b), ndi kuvala abrasive ndi kuvala zomatira kumachitika nthawi yomweyo. Pamene katundu ukuwonjezeka kwambiri, abrasive fumbi la cladding wosanjikiza imayamba kufalikira kumtunda wonse wowonongeka, ndipo kuya ndi kukula kwa ma micropores kumawonjezeka (onani dera D mu Chithunzi 11b). Zochitika zonsezi zikuwonetsa kuti pakuwonjezeka kwa katundu, brittle spalling imakhala yovuta kwambiri, ndipo zokutira zophatikizika sizoyenera kunyamula katundu wambiri.

4 Mapeto

Kuti mupititse patsogolo kukana kwa Ti6Al4V aloyi, laser cladding zokutira linakonzedwa pamwamba pa titaniyamu aloyi pogwiritsa ntchito Ni ndi TiB2 ufa wosakaniza. Zotsatira zikuwonetsedwa pansipa.

(1) Zotsatira za XRD za laser cladding layer zikuwonetsa kuti laser cladding layer imapangidwa makamaka ndi TiB, TiB2, α-Ti, β-Ti, NiTi alloy solid solution ndi TiO2, komanso pakuwonjezeka kwa TiB2 powder ratio, gawo la TiB2. zomwe zili zikuwonjezeka kwambiri.

(2) Chophimbacho chimapangidwa makamaka ndi gawo lakuda la elliptical, gawo lotalikirapo ngati singano ndi gawo lozungulira la ma cell. Gawo lakuda la elliptical ndi TiB2, gawo ngati singano ndi TiB, ndipo gawo lozungulira ma cell ndi NiTi. Ndi kuwonjezeka kwa TiB2 kuwonjezera, zomwe zili mu TiB zimawonjezeka ndipo tinthu tating'onoting'ono ta TiB timakhala tambirimbiri.

(3) Pamene chiŵerengero cha TiB2 ufa ndi 40%, microhardness ya cladding wosanjikiza amafika pazipita 920. 8HV1. 0, yomwe ili pafupifupi 3 nthawi ya Ti6Al4V alloy. Kuwonjezeka kwa microhardness kumathandizira kukana kuvala kwa wosanjikiza wa cladding. Pamene katunduyo akuwonjezeka, kuwonongeka kwa brittle kwa zokutira kophatikizana kumakhala koopsa kwambiri, komwe sikuli koyenera kunyamula katundu wambiri.