NGHIEN CCrU - TRAO DOI XAC DjNH VCiNG GIA TRj HOP LY CClA CAC THONG S C N G NGHE ANH HU'd'NG D^N DO X6P LaP P H O B O T C A C B U A CrjCj - NiCr TREN NEN TRUC THEP 40Cr BANG PHUONG PHAP PHUN 6XY - NHIEN LIEU T C O O CAO (HVOF) IDENTIFY SUITABLE RANGE OF TECHNICAL PARAMETERS FOR THE BEST POROSITY OF CijC^ - NiCr COATING ON C45 STEEL BY HIGH VELOCITY OXY-FUEL SPRAYING (HVOF) METHOD PGS,TS Dinh VSn Chiin Tniofng Dai hgc Mo - Dia chat TOM TAT Hien nay, cong nghe phun phu dang duac phdt trien mgnh a cdc nuac tien tiin tren thi gidi Mot nhimg phuang phdp phun dui?c img dipigpho biin cdc ngdnh cong nghidp hiin la phuang phdp phun HVOF Ve bdn chit, cdc Icrpphun bdng phucmg phdp phun HVOFvo ciing phuc tgp, cdc dgc tinh vd vi cdu true cua lap phit phu thuoc rdt nhieu vdo cdc thdngsd qud trinh phun Trong bdi bdo ndy giai thieu kit qud nghien cuu dnh huong eita mQt sS thong si cong nghe din xdp ciia lop phii Crf^-NiCr tren nin true thep 40Cr bdng phucmg phdp phun HVOF Tii lua chpn dupe ving thong sS cong nghf phun hap ly di phuc hdi cdc chi tiit dgng true bi mon Tir khoa: Phunphu kim logi, phun HVOF, hot cacbua Crfi^-NiCr, lap phu, dp xdp ABSTRACT Spray coating technology has been developed and widely applied in developed countries One ofspraying methods that is most common used in industry is HVOF Basically, coating laye created by HVOF are very complicated, its characteristics and microstructure strongly depen on spraying technical parameters In this paper, effect of some spraying technical parameters to coating porosity ofCrf^-NiCr on 40Cr by HVOF is studied From experimental results, a suitabl range ofspraying technical parameters has been identified that could be applied to recovery shaft type wearing parts Key words: Metal spraying HVOF spraying Crf^-NiCr, coating layers, porosity ISSN 0866-7056 TAP CHl CO KHI VI$T NAM, S6 1+2 nam 2017 www.cokhivietnam.vn NGHIEN cuu - rr -VZ-W-/ DAT VAN ©E Do ben ciia cac chi tidt may la mgt nhung ydu td dnh hudng ddn tudi thg cua thidt bi Do dd, vide phuc hoi lai hinh dang, kich thudc cua cdc chi tidt la vdn dd cap thiet, dugc nhilu nha Idioa hgc va cac nha san xudt quan tam Cd nhilu cdng n ^ d phuc hdi chi tidt nhu; Cdng nghe han dap [1], cdng nghe ma [2], cdng nghd phun phu [3], [4] Trong do, phuang phap phun phii ngdy cang dugc phat trien vd md rgng ve quy md, cai thien vd chat lugng, thd hien tinh uu vidt so vdi cac phuang phap tao ldp phii khdc LTU diem chinh cua cdng nghd phun phii, dac biet la phuang phap phun HVOF, la tao phu cd xdp thip vd bdn bam dinh cao Ddng thai, khdng gdy iing suit nhidt [3] Do vigc nghien ciiu dnh hudng cua cac.didng sd cdng nghe den chat lugng ldp phu la mdt vdn de mang tinh thuc tien cao, dugc nhieu ngdnh va cac nhd ky thudt quan tam nghidn ciiu lLf\Jl va so sanh cac khu vuc vdi tdng dien tich mau dugc Kinh hidn vi dugc lidn ket vdi he thdng may tinh va phan mdm dd phdn tich, xdc djnh gia tri dd xdp cua mau bang cdch chuyen ddi cac vung rd xdp th^ih mau do, phan cdn lai cua cac can tnic te vi dugc chuyen mau xanh (hinh 2) Chuong tiinh may tmh dugc sut dung dd tinh to&i ty Id phdn tram didn lich viing cd mdu hinh dnh V Hinh Qua trinh do xdp lop phu trin kinh hiin vi GX51F PHirONG PHAP NGHIEN CUtJ - Tren thuc te xdp ldp phu thudng dugc tiang phuong phap quan sat gian tidp bing each sir dung kinh hien vi quang hgc, kinh hien vi di$n tir quet, hoac bang ky thuat tdn xa X-ray De xac dinh dg xdp cua ldp phu, mdu dugc cat dd quan sat theo tiet dien be mat ldp phu Sau cat, man dugc gia cdng bd mat tr6n cac lo^i gidy rap cd kich ca tur hat thd ddn h&t min, dugc danh bdng trdn cac may chuyen dvng ddm bao khdng cdn vdt xudc trdn bd mat, dat yeu cdu ky thudt Sii dyng kmh hiln vi quang hgc GX51F (hinh 1) dd dd xdp lop phii Qua tiinh dugc thuc hien theo tidu chudn JIS-H-8664 - 1997 (Nhdt) Do xdp dugc true tidp di$n tich cac Id xdp khu vuc quan sat ciia kinh hidn vi Hinh Anh chup kit qud do xdp lop phu KET QUA VA BINH L U A N Qua trinh do xdp ldp phu bdt cacbua Cr3C2-NiCr tren ndn true thep 40Cr bdng phucmg phap phun HVOF, dugc thuc hidn trdn kinh hidn vi GX51F cd su hd trg cua mdy tmh va phdn mdm chuyen dung, Kdt qud 27 mdu thuc nghiem dugc thS hien bang '^ ISSN 0866 - 7056 TAP CHi CO KHi VIET NAM, Sd 1+2 nam 2017 www.cokhivietnam.vn NGHIEN CU'U-TRAOD6I Bdng Kit qud do xdp ciia ldp phu bdt cacbua Crf.^ - NiCr trin nin trgc thep 40Cr bang phuomg phdp phun HVOF TT 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Ma 11 21 31 41 51 61 Nhom thire nghifm m (gam/phiit) n (vong/giSy) S (mm/v6ng) «(%) 25 25 1 3,2233 25 25 1,5533 2,7100 25 25 25 2 3,0625 1,2994 2,3660 3,0966 1,3188 2,3763 Nhom thuc nghiem so 71 81 91 12 22 32 42 52 62 72 82 92 13 23 33 43 53 63 73 83 93 Nhom thuc nghiem so Nh6mthue nghiem so 3 3 25 25 35 35 35 35 35 35 35 35 35 45 45 45 45 45 45 45 45 1 2 3 1 I 2 3 45 9 9 * 9 3,1718 1,4617 2,5850 3,0140 1,2500 2,2633 3,1287 1,3586 2,4521 3,1093 1,3752 2,4670 3,0756 1,2776 2,3248 3,1920 1,3933 2,4867 Tit cac ket qua nghien ciiu a tren, ti6n hanh xay dung dugc cac d6 thi biSu diln m6i quan he giiia xop ciia lop phu vol cac thong s6 cong nghe nhu: Luu luong cip bot phun (m); t6c dp quay cua phoi (n), toe dp dich chuySn cua diu phun (S) Tren cac hinh 3a, hinh 3b vi hinh 3c la cac d6 thi 3D mo ta su phu thu6c giiia dp x6p ciia 16p phu dSn cac thong sd cong nghe phun Qua c6 thi nhan thiy ro anh hucmg d6ng thai cua thong so phun (m, S va n) miSn khao sat, cac ducmg dac tmh la nhftng duong cong khong gian chieu, CO diem cue tri ISSN 0866 - 7056 TAP CHl CO KHl V I £ T NAM, S6 1+2 nam www.cokhivietnam.vn 2017 NGHIEN CLfU - TRAO £.wi Hinh 3d Quan hi cua xop ldp phii vdi cdc thdng sd phun (m) khong doi Tii dd thi hhih 3a cho thiy, tang ddng thdi ca hai thdng sd phun (n) va (S), ihdng sd phun (m) khdng ddi, thi Id mdt dudrng cong bieu didn dd xdp lap pM gidm nhanh va dat cue tri Idioang S=6 (mm/vong) Hinh 3b Quan hi cua xdp lap phu v&i cdc thong sd phun (S) khdng ddi Tai hinh 3b cho thdy, Idii tang ddng thdi cd hai thdng sd phun (n) va (m), thdng sd phun (S) khdng ddi, dd thi la mdt dudng cong bieu diln dd x6p ldp phu giam nhanh d giai doan ddu va gidm cham d giai doan sau vd dat circ trj khoang n=2 (vong/gidy) ^ f %ml Sfnohwitf mwmVMl Stnmhtng) nlgintlHt) HinhSc Quan he cua dg xdp l&p phu v&i cdc thdngsd phun (n) khong doi Tai hinh 3c cho thay, tang ddng thdi cd haitiidngsd phun (S) va (m) thdng sd phun (n) khdng ddi, dd thi Id mdt dudng cong bieu diin xdp ldp ph'u gidm nhanh va dat cue tri khodng S=6 mm/vdng Cd the gidi thich hidn tugng ndy nhu sau; Khi tdc dd quay ciia phdi (n) va tdc dich chuyen ciia ddu phun (S) tang khoang hgp ly, ldp phun se tao thdnh dudng xoan dc chdng chdt len nhau, dam bao dien tich ldp phun sau chdng Idn 1/3 dien tich ldp phun trudc, tao dieu kien thudn loi cho su lien ket giiia cac hat phun vdi bd mat ndn hoac bd mat ldp phu cd tCr trudc, ddng thdi, mat cua cac hat ndng chay dugc phan bd ddu tren todn bg be mat nen khdng gay hidn tugng qua ndng tren be mat cua chi tiet, cdc Id tich tii ldp phu se dugc diy ngoai lam cho ldp phu cd dd xdp thdp va bdn bam dinh cao Tuy nhidn, tdc dd quay cua phdi (n) va tdc dd dich chuydn cua ddu phun (S) tang qua Idn ddn^ ISSN 0866 - 7056 TAP CHi CO KHI VIET NAM, Sd 1+2 nam 2017 www.cokhivietnam.vn NGHIEN CO'U-TRAO D O I ddn cac dudng xoan dc ciia ldp phun khdng chdng chit len nhau, dd tai viing tidp giap giua cdc dudng xoan dc lop phu xuat hien cac Id tich tu lam cho dd xdp ldp phu tang, dd ben bam dinh gidm, KET LUAN Qud trinh nghien ciiu thirc nghidm da xdc dinh dugc cdc gia tri vd dd xdp ldp phii bdt cacbua CrgC^ - NiCr tren nen true thdp 40Cr bang phuang phdp phun HVOF Tir ket qua va phan tich anh hudng cua cac thdng s6 cdng ngh?, da xay dung dugc dd thi dang 3D phdn anh mdi quan he giua xdp ldp phii vdi cac thdng sd cdng nghd (m, S vd n), tir l\ra chgn dugc cac vung thdng sd cdng nghe phun hgp ly cho ldp phu cd xdp thip nhdt vdi gia tri cua cac thdng so phun dat cue tri khoang S^6 (mm/vdng) va n=^2 (vdng/gidy); cdn thdng sd phun m cd anh hudng khdng dang kd Ket qud nghien ciiu cd the 1dm tai h^u tham khdo ph^c vu cho vide giang day, nghien ctiu khoa hgc Hnh vuc chuyen nganh • Ngdy n h ^ bai: 05/02/2017 Ngay phan bidn: 18/02/2017 Tai lidu tham khao: [1] [2] [3] [4], Hoang tung (2006); Gido trinh Vdt lieu va cdng nghe hdn, NXB Giao due Nguyin Van Ldc (2007); Cong nghi ma dien, NXB, Giao d\ic Hodng Tiing (2006); Cdng nghe phunphu vd ung dung, NXB Khoa hgc vd Ky thu^t, Ha Ngi Dinh Van Chidn, Dinh Ba Tra (2014); Ky Thugt phun nhiet tdc dg cao HVOF, HVAF, D-Gun, NXB Khoa hgc & Ky thuat, Ha Noi ISSN 0866 - 7056 TAP CHi CO KHi VlfiT NAM, Sd 1+2 nam 2017 www.cokhivietnam.vn ... xdp lop phu KET QUA VA BINH L U A N Qua trinh do xdp ldp phu bdt cacbua Cr3C2- NiCr tren ndn true thep 40Cr bdng phucmg phap phun HVOF, dugc thuc hidn trdn kinh hidn vi GX51F cd su hd trg cua mdy... tdc dich chuyen ciia ddu phun (S) tang khoang hgp ly, ldp phun se tao thdnh dudng xoan dc chdng chdt len nhau, dam bao dien tich ldp phun sau chdng Idn 1/3 dien tich ldp phun trudc, tao dieu kien... NGHIEN CU''U-TRAOD6I Bdng Kit qud do xdp ciia ldp phu bdt cacbua Crf.^ - NiCr trin nin trgc thep 40Cr bang phuomg phdp phun HVOF TT 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Ma 11