Hard alloy exceeds the experimental research of accurate mirror grinding

As a result of the hardness of hard alloy big, tenacity differs tall, brittleness, processability can be poor, use traditional method to satisfy the technical requirement of nicety and superprecision hard, and working procedure much, efficiency low, cost is high. Apply technology of ELID accurate mirror grinding to machine all sorts of hard alloy, grinding figuration, the result is favorable, exterior surface roughness amounts to Ra10 ～ 20µm generally, and efficiency tall, cost is low, not tall to requirement of machine tool precision, have huge to popularize value and applied foreground. One, hard alloy exceeds data of test of data of test of test of accurate mirror grinding to see a table 1. HRA of hardness of MPa of bending strength of G/cm2 of density of WC TiC Co of function of machinery of brand composition physics pounds the sort of physical machinery function that expresses a few kinds of 1 typical hard alloy line of M/cm2 of tenacity Kg · bilges 300 ℃ of coefficient × 10-5(0 ～ ) WC-Co YG8 92 8 14.

4 ～ 14.

8 1500 89 0.

25 4.

5YG20C 80 20 13.

4 ～ 13.

6 2200 82 WC-TiC-Co YT14 78 14 8 11.

2 ～ 12.

0 1200 90.

5 0.

07 6.

21YT30 66 30 4 9.

35 ～ 9.

7 900 92.

5 0.

03 steel written guarantee hard alloy GT35 35 6.

40 ～ 6.

1800 85 of 60 1400 ～ .

5 0.

6 experiments condition and parameter are in MM7120 lie on grinder of plane of axial quadrature stage, the unit of ELID planar grinding that adds design of outfit proper motion, undertake to afore-mentioned brand hard alloy ELID exceeds experiment of accurate mirror grinding. Experimental condition and parameter see following: The MM7120 that experimental equipment changes his costume or dress planar grinder abstains W10 of CIFB emery wheel, w5, w1.

5 abstain HDMD-II ELID grinding power source of pulse of special and high frequency dc abstains 1440r/min of rotate speed of main shaft of parameter of grinding of HDMY-201 grinding fluid transverse feed speed 0.

Speed of workbench of journey of 1 ～ 3mm/ 0.

05 ～ 0.

08m/s grinding deepness 0.

001 ～ 0.

005mm electroanalysises parameter voltage electric current of 45 ～ 125V 0.

5 ～ 6.

5A electrode clearance 0.

1 ～ 0.

75A test result uses afore-mentioned equipment conditions, electroanalysis through adjusting parameter and grinding parameter, undertake ELID exceeds accurate mirror grinding. Use Japanese KosakaLaboratory Ltd.

The SE-3H that the company makes contourgraph undertakes exterior surface roughness detect, ～ of V=20000 of multiple of microcosmic dimension enlarge 50000, walk along H=10 of multiple of paper direction enlarge, sampling length Ro0.

25 ～ 0.

3mm, measure length L=2.

5mm. The workpiece after grinding reachs the lens range of Ra6 ～ 17nm. Detect the result sees a table 2. Express 2 hard alloy to exceed accurate mirror grinding to measure Ra(µm) YG8 6 YG20C 17 YT14 9 YT30 13 GT35 12 of brand of data hard alloy 2, hard alloy exceeds rigid lens face to machine mechanism to analyse ELID nicety in mirror grinding, because grind bead to originallying,be on one hand in bond, wear to the solid of odd grain wear bead and character, in grinding its are effective the 1/3 that grinding dimension wears a size only, wear bead main the means purify material with small cutting, the broken area that bead grinds to cause below means of this kind of grinding so wants small much; On the other hand, emery wheel surface electroanalysises generated oxidation film has certain flexibility, maintain certain ply from beginning to end, and be accommodated among them and bear holding the abrasive that falls off because of electroanalysising a certain quantity ofly in the palm, oxidize film becomes a kind to contain imperceptible abrasive to have good and flexible abrade film. When essence of life is ground, because feed is very small, the ply of oxidation film is far the height giving blade that is more than abrasive, make abrasive of surface layer of emery wheel matrix as not direct as workpiece in grinding contact. The film of this insulation oxidation that covers on emery wheel will replace metallic radical emery wheel to participate in true grinding course. Should electroanalysis when action is restrained completely, oxidation film undertakes to workpiece light is ground. So, ELID grinding is one kind is ground actually, grind, cast combine the aspect of lens of complex formula nicety that is an organic whole processing technique, wearing bead among them basically is with material of workpiece of slip means purify, if pursue,1 is shown. 3, conclusion uses ELID grinding technology to machine hard alloy, the high quality of class of attainable accept rice machines the surface, through controlling grinding parameter is mixed electroanalysis the condition such as parameter, realize the accurate superprecision of high accuracy, low cost. This method avoided passivation of the emery wheel in traditional grinding craft, jam the treatment surface brittleness that cause is destroyed, can replace conventional abrade polish technology, great and economic value is had in the accurate superprecision domain of hard fragile data. CNC Milling