ảnh hưởng của điện áp đánh lửa và cường độ dòng phóng tia lửa điện đến chất lượng bề mặt thép không gỉ SUS 304 khi gia công trên máy cắt dây tia lửa điện

TAP CHt KHOA Hpc & C6NG NGH$ CAC TRITONG BAI HpC K? THUAT * S6 90 - 20J2 THE INFLUENCE OF IGNITION VOLTAGE AND DISCHARGE CURRENTS ON THE SURFACE ROUGHNESS IN PROCESS OF MACHINING STAINLESS STEEL SUS 304 BY WIRE EDM MACHINES ANH HUONG CUA DigN AP DANH L(SA VA cUdNG DO D6NG PH6NG TIA LO'A DI$N DEN C H A T L U O N G Bt M A T T H S P K H O N G GI SUS 304 KHI GIA C N G T R ^ N M A Y C A T DAYTL\LtrADI$N, TYan Van Dich, Luu Quynh Trang Ha Noi University of Science and Technology Received February 28,2012; accepted August 01,2012 ABSTRACT This paper pmvides a mathematical model, describing the simultaneous influence of two parameters which are the ignition voltage (U^ and discharge currents (IJ on the surface quality of SUS 304 stainless steel when it Is processed by wire cutting machines To get this result, the authors have conducted the pmc^ssing of stainless steel using GS2532B wire cutting machines with the input parameters U^ and U set one by one at and max values After processing, the pmducts were measured for surface roughness (RJ \Mth the measured data, orffiogonal experimental planning and construct equation were used to show the dependence of Ra on Uz and Ig In addiSon, ffte authors used the Matlab software to create 3D grap/is to descaibe the relationship between Ra and Uz, 1^ According to the equations and graphs published in this paper, engineers and technicians can establish a set of appropriate parameters of U^ and U to give products a specific roughness after being processed Keywords: Wire EDM; Surface roughness; Optimization; T M TAT Trong bdi bdo ndy, tdc gid dUarami hlnh todn hgc, md td inh hi/dng dong thdi cQa hai thdng s6 la iS§n dp ddnh Ida (UJ vd ddng phdng ba /i>a df#n (Ig) din chit lugng bi mgt th6p SUS304 gia cong trin mdy c:it day h'a /i>s (S$n Bi cd ducyc ket aud dd, tdc gid di tlin hinh gia c6ng thdp SUS 304 trin miy dt diy GS2532B vdi cdc gii trj thdng sd diu vio U^ vi la lin lugi thay dii d dieu kl$n blin Sau gia cdng, chi Hit ducfc di? nhim bi m§t (Rg) Vdi si ii^u dlrgv:, tic gii dUng phuong phip quy hogch thi/c nghi$m tn/c giao, xiy dung phuxmg trinh, chl s y phg thu^c cOa Ra vio U^ vd V Bin cgch (36, tic gli dOng f^in mim Matlab xSy dung di thi 3D biiu diin mil quan hi cOa Rg vdi Uj vi /« TTieo phuong trinh vd tSJ thi dirgv: cdng bi bii bio niy, ngudi ldm cdng nghi cd thi xic djnh c^rgc mit bi thing si (/, vi U phd hgp di dim bdo gia cdng chl tiet (3$t yiu ciu di nhim eg thi TCr kh6a: Wire EDM; D$ nhdm b l m$t; Tdi u-u h6a; INTRODUCTION Electiical discharge machining is one of tiie most effective L o n g non-traditional madtining methods With superior technology capabilities, this method has been widely Expired in developed industrial countries However, our country today suffers from the lack of Wire EDM madunes as well as reference documents about wire EDM methods hi addition, technology transfers of tiie equipment by suppUers are not c o m p r e ^ i v e enough leadmg to fiutiier difficulties fi)r tiie users [ j Stainless steel SUS 304 has many advantages such as: tiie high corrosion resistance, non-magnetic properties, flexible, easy to weld, and therefore used widely in the engineering and building industry In the JAP CHl KHOA Hpc & C6NG NGH? CAC TRU'ONG DAI HpC K* THUAT • S6 90 - 2012 machining of SUS 304 by Wire EDM machines, the workers rely solely on their personal experiences and thus the surface of the products after machining usually does not meet quality requirements Table J- The main technical parameters < Goldsun GS2532B machine No The main technical parameters Table dimensions (L*W) Table travel Max thickness of work piece Max process taper Molybdenum wire diameter Max process speed Surface roughness Process accuracy Max process current 10 Power requirement 11 Packmg dimensions of machine 12 Machine weight 13 Packing dimensions of controller 14 Controller weight In order to help workers and those who would like to determine the appropnate ignition voltage value U^ and discharge currents L to achieve the specific roughness, the authors conducts the research "The influence of ignition voltage and discharge current on surface roughness in process of machinmg stainless steel SUS304 by wire EDM machines" APPROACH AND EXPERIMENTAL SETUP Based on the theory of method of orthogonal experimental plannmg, 2k type [2J, the authors perfoimed the processing of woric piece on a wire cutting machine with four tests, in each expenment, input parameters values Uz and Ic are set one by one at and max values Then, surface of product was measured the roughness With the measured data, the authors construct a equanon, shows the dependence of R on Ui and L Finally, with the support of the Matlab software the authors drew the 3D graph which describes relationship of R with Uz and I 250*320 mm 400 mm (Adjust) 6" & 10° 0.1-0.2 mm