T^P CHI KHOA HQC & CONG NGHE CAC TRUGWG DAI HOC KV THl'AT • SO 92 - 2013 KHOAN LO SAU TREN HOP KIM NHOM CO TRO GIUP CUA RUNG DONG TAN SO THAP MANUFACTURING DEEP HOLES ON ALUMINIUM ALLOY BY LOW-FREQUENCY VIBRATION ASSISTED DRILLING Pftan Van Nghi, Nguyen I an Dir Trmng Da! hgv Kv thual Cong nghi^'p, DHTN Lc Duy Hoi Trudng Cao dang Kinh lc Ky thual, DHTN Bat bao gidi thidu mpt wng dpng eua rung ddng cht phi thap nhdm tra giup khoan Id sau tren hap kim nhdm AA5052 Mdt ea ciu Idch tdm ed thi tao rung ddng tu- 26 din 60 Hz, bien dd tw din 12 micromet dwac tieh hgp nhdm tao rung cho phdi theo phwang dpc true mui khoan Cac lo co dw&ng kinh 1,5 mm va chiiu sau 13 mm, cd ty sd UD xap xi da dwac gia cdng bang khoan thwang va khoan cd bd sung rung dgng So lieu tht/c nghiem vi dd lay ddng dwdng kinh va tron Id khoan dwac phan tich so sanh thdng qua kidm nghidm so sanh t (2 sample t-test) tren 18 mdu Kit qua cho thiy khoan co rung cd thi lam giim dd lay rdng dwdng kinh Id din lin lam giam dd khdng trdn cOa Id din lin so vdi khoan truyin thdng Hidn tuung ket hoac gay mui khoan thwang thiy khoan cung khdng cdn cd rung ddng trcf giup Kha nang nang cao nang suit, chit Iwong khoan Id sau tren edc vat lidu deo, khd gia cdng vdt chi phi thip trd ndn rat hwa hen Tiy khoa' Khoan 16 sau, Hap kim nhom, Rung dpng tra giup gia cong khoan ABSTRACT This paper introduces an application of low-cost vibration assisted deep drilling for aluminum alloy AA5052 An eccentric rotary mechanism was used to induce vibration for the workpiece The vibration was integrated in feeding direction with a frequency range from 26 to 60 Hz and an amplitude range from to 12 micrometers Holes with UD ratio of 9, with diameter of 1.5 mm versus depth of 13 mm, have been machined in both methods of conventional and vibration assisted drilling Oversize and diameter vanants of holes obtained from 18 samples were then analyzed and compared using the sample t-test method The results showed that, compared to conventional drilling, vibration assisted dniling can reduce the oversize ratio by as much as times and also by times for the out of roundness of the holes The tool jam and tool crash, which are usually occurred in conventional dniling, had not been happened in cutting with vibration assisted This implies a very promising and low-eost way to enhance production rate as well as high quality in drilling diffieult-to-eut matenals using vibration assisted Keywords Deep dniling, Aluminium alloys, Vibration Assisted Driiling L GlCfl T H I E U ,J J J ,, , H a p kim nhom dang d u a c su dung "^ , , ,°, ' ' ° ".-^ cang rong rai cac linh vuc cong nghiep ^ cat • got hgp • kim onhom o r^ Noi chung, gia cong de dang va co nang suat cat cao han so vai cong thep va cac h a p kim den, Tuy nhien, *' u J• r 1• 1- 1 tmh deo cua h a p kim n h o m , gia cong khoan vat ,- - ^r -• ' ; ji ; lieu t h u a n g gap phai cac van de ve nang - • L-^ r i?i r n T• • L suat va chat luong lo khoan 111, Trong qua tnnh 1, • I; •; • 11 - • • ' khoan, phoi khong the thoat khoi vung cat , , J , , , ^ mot cach tu n h u cac dang gia cong l u ' ni •.-'1 • ,- ' J ' \ •' • L khac Phoi ( t h u a n g la phoi day) co ma sat manh vai mat truac mui khoan, ranh xoan thoat phoi ,, , ,s,, , • , - JI • X ' va lo khoan, cang can t r a dong phoi thoat ra, bam chat vao ranh xoan lam tang mo men xoan, dong thai lam phat sinh cac lire day ngang mui khoan Luc ma sat cOng lam tang luc ? r-?! r-.'• -'.i ^ - i L cat 121 Dieu co the gay ket hoac xoan gay „.\ ,, " , • , j^ui khoan Hon nua, ma sat cua phoi day len 16 khoan phoi thoat se cao xuac vao ,s , ,be mat ' , ,16 khoan , lam •-tang Ldo• nham Jbe •• mat - lo khoan Ma sat Ion giua phoi day vai mat , „ , i -• , - •• u - i \truac, vol ranh xoan mui khoan va voi lo ,, , , i •- i ,i • khoau COU lam cho nhiet cat tang nhanh, gay , _.,, ,•• - •? i L