Nghiên cứu độ bền bám dính của lớp phun phục hồi với kim loại nền chi tiết trục bằng phương pháp phun nổ

NGHIEN CUfU-TRAO D I NGHIEN c u t ; D O BEN BAM DINH CUA L O P PHUN PHUC HOI VOII KIM LOAI NEN CHI TIET TRUC BANG P H C O N G PHAP PHUN NO STUDY OF BOND STRENGTH OF THE COATINGS ON THE SURFACE OF THE WORKPIECE CAMSHAST BY DETONATION SPRAYING METHODE TS Dinh Van Chi^n\ ThS Pham Van Lieu^ 'TrUcfng Dai hoc Mo Dia ehat ^TrUdng Dai hpe Cong nghiep Sao Do TOM TAT Phun no Id mdt phUdng phdp phun phuc hoi chi tiet rdt co hieu qud tinh bdm dinh cua ldp phun vdi ldp nen Bdi bdo trinh bdy ket qud nghien cdu ben bdm dinh cua ldp phu hot Cr20Ni tren mdu vd tren chi tiet true cam xe tdi Bd nghien cdu thiet ke che tgo dogd sung phun bdo ddm cdc thdng so tdc dich chuyen cho ddu phun vd khodng cdc phun Dd tie'n hdnh phun vd xdc dfnh ben bdm dinh cua ldp phu Ket qud khang dinh ben bdm dinh ddp dng yeu cdu chdt ludngphuc hoi chi tiet Sdn phdm phuc hoi da dUdc dng dung tren xe tdi ldm viec tgi Cong ty Than Qudng Ninh Detonation spraying is an effective methodefor restore machine parts dimention, that is because of the bond strenghs of the coatings on the surface of a workpiece This paper present the study results of the coating layers Cr20Ni5 powder on the Camshaft The fixture is designed and produced for control of velocity and distance among detonation gun and surface of workpiece The study was determined effects of conditional technology on adhesion in the coating layers The project suggested that it has been applied for mechanical manufacturing companies in VINACOMIN Quangninh Gl6l NO Bdng Ddc tinit ky thudt cua phun no THIEU PHUN I'hun nhiei - No Phun no, mot dang eiia phun nhiet oxy chiy toe cao (High Velocity Oxy-Fuel-HVOF), la c6ng ngh^ phun phu be m^t chi tiet vdi nhieu muc dieh khic nhau, do, dung de phuc hoi cac be m?t chi tiet mon hong Phuong phap phun no TAP CHf Nguon nhiel Su no hon hop oxy- nhien lieu Chieu day phun phii, mm 0,01-2 Do xop, % 70 Vat li?u phun Cac v?t li?u bpl Toe dp hat phun, m/s 700-1200 Nhi?I dp chay, "C 2800-4000 Khoang each phun ni 2,00 Toe dp dong phun m/s 3000 Nhi?t dp tren be m^t, "C 200 Chl phi Trung binh CO KHf V I £ T NAM So 1+2 (Thang H nam 2013) NGHIEN CUfU - TRAO 061 dupe sd dung rgng rai tat ca cae nganh eong nghiep; Che tao may, hang khong, ten Ida, dong tiu, dau khi, luyen kim w Phun no co cie Uu diem (bang 1): Gia ha, nang suit lao dpng eao, to ehdc die it xop, dp ben b i m dinh tot, CO the cho ldp phu diy Mpt cie yeu cau ehat lUpng eua eong nghe phun phu la ldp phu phai diipc bam dinh chat vdi be mat kim loai nen De dat dupe dieu do, ap suat cua cie hat phun tai thdi diem tiep xue vcfi be mat vat dupe phun phai du ldn, nhd nang lupng va dap, lam nong chiy be mat ti^p xuc v i tii dd tao sU lien ket ben vdng giCta vat lieu phun va vat lieu nen Dau phim no (hinh I) gom cac bp phan chinh sau: Mot buong dot, dUpc dan cie oxy va chiy l i m ngudn nang lUpng, bugi kich Ida, cac binh ehda bot phun, he thong van dieu khien, cac binh ehda khi, he thong dieu khien dien va thuy lUc Dau phun no dUPe dit tren mpt gii dd CO k h i ning dieu ehinh dUpc chieu, phu hpp vdi vi tri phun eua ehi tiet can phun Hmh L Sd ket cdu ddu phun no vd qud trinh phun CO SO HINH THANH LOP PHU Hinh Sd hinh thdnh ldp phu Nguyen ly hinh thinh ldp phun phu no: Khi oxy v i axetylen dupe trpn vdi mpt ty le nhat dinh, du tao hien tUpng no, dupe bugi kich boat, hdn hpp bi chay dot ngpt, gay hien tUpng no San pham cua phin dng chay la co ap suat cao v i nhiet cao Khi ehay dan nd nhiet nong, keo theo tro va bpt phun Bpt phun dupe gia tdc va gia nhiet den nhiet dp nong chiy ehung bay khdi nong va den b i m vao mat chi tiet Toe dp dau nong cang ldn, toe dp bay eua bpt phu cang eao, toe dp va dap vdi be mat vat pbii cang cao Khi cac gipt kim loai long va dap len be mat chi tiet, ehung se bam vao v i dong die Toe dp va dap vdi ehi tiet phu thupc vao khoing cich td dau sung phun den chi tiet Hinh Hinh to chiic tevi Idpphu TAP CHf CO KHf VIET NAM S6 1+2 (Thang 1+2 nam 2013) NGHIEN CUfU-TRAO Ddi Ldp phii dupc hinh tii tdng khoi nho kim loai phu, dupc dap sit va chong chat len nhau, hinh I ldp phu (hinh 3) Chi tiet phai dupe quay v i dau phun phii dich chuyen, ldp phu CO d^ng xoan xep chong len De tang dp b i m dinh, hi mat chi tiet phii dupe lam saeh v i cd the lam nhim Khi kim loai phu b i m dinh d tren be mat chi tiet d nhiet dp cao, se ed hien tUPng khuech t i n eua cic nguyen td chat phd vio kim logii nen Q u i trinh khuech tan cang lam ting dp bam dinh gida ldp kim loai va giCta cac ldp phu vdi Ngoai dp ben b i m dinh phu thupc hinh ding hinh hoc ehi tiet phun Dp bam dinh eon phu thupc vao hinh dang be mat chi tiet Cae ehi tiet phang cho khoang cich tUPng doi dong deu qua trinh phu, cdn chi tiettron xoay tao nen khoang each td dau phun den diem va d i p khic nhau, dUdng kinh ehi tiet cang nhd, sU khie biet khoing each tUPng doi cang ldn, nen can khong ehe de tao sU bam dinh ddng deu NhU vay, dp hpi tu chat phun phu thupc vao b i n kinh eong chi tiet phun Che dp phun phai phdi hpp sU dieh ehuyen eua dau phun va ehi tiet phun Tde dp quay cua chi tiet va tdc dp dieh chuyen eua sung phun phai b i o dam cac vung dUpc phun chong len nhau, khong dUpc co khoang each Hinh Quy dgo phun vd sUphdn b6 chat phu Do cac phan td chat phun mang nang lupng eao va dap vao mat chi tiet can phun, nen tdc dp va dap cd tinh quyet dinh den dp bim dinh vat chat tren be mat, biet rang E = l/2mV^ Tdc dp va dap cua cae phan td chat phun cd the tinh theo eong thdc sau [3]: khdi bot phu, A^- tiet dien ngang trung binh eua khoi bpt phu Ap lue eua khdi bpt tie dung tai vung tiep xue dupc tinh (5]: p c, (3) ^ " Pp^.?^'p(^ + - ^ ) Trong do: c v i (1) c^^ la toe dp am cua vit lieu phu va vat Trong do: V - tdc dp eua phan td va dap, Heu nen m/s, C - ty nhiet, eal.g' "C '; t, - nhiet dp phan td tai thdi diem va dap, "C; t^ - nhiet dp ndng chay cua kim loai, "C; S - enthalpy, cal.g ' r;=9yC^(r,-fi)+5 Dpng lupng cua khoi bpt phun dUpc xic djnh theo [4]: dv dv CnAM^'V^ uo - — - = w-v- — - - — " dt " " dx (2) Hinh M&u thit hen bdm dinh P H i r O N G P H A P T H l J C N G H I E M Trong do: m - khoi luong trung binh cua TAP CHf r n KHi V I £ T N A M a Vat lieu phun: ThUc nghiem sC( dung vat's S6 1+2 (Thang 1+2 nam 2013i NGHIEN CUfU - TRAO D | lieu bgt hgp kim Cr20Ni3, co phan 20%Cr, 2,5-3,0%Ni, lai la Fe Do hat trung binh 40|im < < lOO^im (Hinh 5) Sau lap rap chft va ao ngoai, ngUdi ta phun len be mat chung Ti^p sau dUa len thiet bi de keo chot khoi ao ngoai Do ben lien ket dugc tinh theo cong thiic: b Mau vat lieu phun thfi nghiein: Muc dich phun phuc hoi true cam, nen phan mau tuong duong v6i thep 40Cr c Cach xac dinh ben bam dinh giiifa Idfp phu vofi kim loai nen: Sif dung phuong phap keo chot 4P (4) Trong do: P - LUc keo p h i buy, MPa; d - Dudng kinh tiet dien 16 O, Htnh Chl tiet cdn phuc hoi vd thiet bf phun no d Thiet ke che tao ga: ga sung phun va ga chi tiet Chi tiet phun phai dUpe ga len g i , chi tiet dupc quay vdi mpt tdc dp nhat dinh Sung phun dupe dieu chinh chieu: Chieu eao tam sung nim tren cung mat phang ngang cua tam true ehi tiet va true tam sung vuong goc vdi true chi tiet; dieu ehinh khoang each td dau mieng siing den be mat chi tiet va eo the dich chuyen ngang Toe dp quay cua chi tiet va toe dp dich chuyen ngang eua sung dUpe khong ehe theo dddng kinh chi tiet Vdi chi tiet true cam, c6 the dieu ehinh so vong quay td 70-90vg/ph, toe dp dich ehuyen ngang cua sungl,7mm/vg " ' > Hinh Dogd sungphun vd dogd chi tiet phun Cong nghe phun phu thUc hien nhU so hinh Che phun dugc thuc hien tren co sd vung toi Uu cong nghe da riit tU nghien ciiu: - Toe dp phun tai dau nong dieu chinh khoang 800~1200m/s; - LUu lugng bgt phun : 400-500g/s; - Khoang tii dau nong den chi tiet: 100~300mm TAP CHf CO KHf VIET NAM ôô> ã (MOD Z^