Study On Fixed-abrasive Wire Polishing Technology Adopted To Small-aperture Diamond-coated Wire Drawing Mold

Diamond-coated wire drawing mold has superior wear resistance,and its service life is much longer than others,so,diamond-coated wire drawing mold is an important tool in drawing industry.But the diamond film prepared by chemical vapor deposition method is polycrystalline,and its surface roughness value is very high,so the diamond-coated wire drawing mold cannot be used directly before polishing.However,the efficiency of free-abrasives wire polishing method adopted to small-aperture diamond-coated wire drawing mold is low,therefore,fixed-abrasive wire polishing(FAWP)method is proposed in this paper,which utilizing the scratch effect of grains to polish diamond film.In this paper,the basic theory of FAWP was studied firstly.A polishing machine was designed secondly.Polishing effect of FAWP and failure forms of electroplate diamond wire were studied thirdly.The processing craft of FAWP suitable for diamond-coated wire drawing mold was studied finally.The main work and achievements are as follows:(1)The basic theory of FAWP was studied.At first,polishing mechanism of FAWP was researched,and its feasibility was verified by experiments.Then,the main influencing factors of polishing effect were analyzed,and the characteristics and application of FAWP were summarized.(2)The polishing machine was developed.Utilizing modular design method,the machine was divided into four modules,including mold clamping module,mold moving module,diamond wire regulating module,and machine body module,and each module was designed separately.After reassembling,the polishing machine was successfully developed finally.(3)The polishing effect of FAWP and failure forms of electroplate diamond wire were studied.FAWP was adopted to polish diamond-coated wire drawing mold,its material removal rate(MRR)was 2 times larger than that of the control group(Free-abrasive wire polishing),the surface roughness value of diamond film after polishing by FAWP was Ra 0.43 ?m,which was lower than that of free-abrasive wire polishing(1.52?m).The results showed that,the polishing effect of FAWP was better than that of free-abrasive wire polishing.And,the main failure forms of electroplate diamond wire were analyzed according to experimental phenomenon.(4)The polishing craft of FAWP suitable for small-aperture diamond-coated wire drawing mold was studied.At first,1200# electroplate diamond wire was selected to polish diamond-coated wire drawing mold,and the optimal polishing time(1 hour)was found.Then,the optimized process parameters were studied through single-factor experiments,and the optimal parameters were shown as follows: rotate speed 1300 rpm,reciprocating frequency 40 times,tension of diamond wire 20 N,and the surface roughness was reduced form Ra 4.1 to Ra 0.32 after the diamond film was polished for 1 hour.