One, the influence of polishing fluid constituent to polishing effect 1. Vitriolic pH indicator affects different pH indicator vitriolic the weightlessness to yellow sheet copper and the influence curve that reflection leads are like graph 2-18 place to show. See by graph 2-18, vitriolic presence is measured certainly in polishing fluid, increased the proportion of solution and viscosity, be helpful for brass surface of around mucus film form, achieve polishing result thereby. In the meantime, vitriolic also rise to corrode action certainly. Increase along with vitriolic pH indicator, weightlessness quantity of the metal increases gradually, the reflectivity of brass surface or brightness are parallel also rise. If vitriolic chroma is exorbitant, cause polishing fluid viscosity too big, brass deliquescent quantity decreases instead, polishing speed is decelerated, reflectivity also drops subsequently, although have,make smooth outward appearance right now, but lacklustre, accordingly, by graph 2-18 we can be decided first-rate is vitriolic chroma should be between 33%~41% . 2. 2-19 of graph of influence of nitric acid pH indicator is nitric acid chroma to brass piece the influence curve of weightlessness and reflectivity. See by graph 2-19, nitric acid rises already corrode action to have shining effect again. Increase as nitric acid pH indicator, deliquescent quantity of the metal increases gradually. When the chroma of nitric acid is inferior, deliquescent quantity of the metal is little, the density of ion of the metal in polishing fluid is low, form mucus film not easily, polishing effect is poor. When nitric acid chroma is exorbitant, metallic surface is corroded easily too, brightness is reduced. When nitric acid chroma is 4%~6% , the reflectivity of brass surface is highest, brightness is best. 3. The content of the in affecting polishing fluid water of water content is right brass piece if the influence of weightlessness and reflectivity pursues 2-20 place is shown. See by graph 2-20, the content of water affects shining action likewise, its content is when 53%~56% , polishing effect is best. When the content of the water in polishing fluid is overmuch, the viscosity of polishing fluid drops, mucus film is destroyed, cannot get shining metallic face. Additional, as the addition of content of the water in polishing fluid, the acerbity chroma in solution by dilute, slow down acid is right of the metal corrode action, cause deliquescent quantity of the metal to be reduced gradually. 4. Chroma of FH-5 of influence of FH-5 pH indicator is right brass the influence curve of weightlessness and a reflectivity is shown at graph 2-21. See by graph 2-21, metallic weightlessness follows the change with FH-5 only and slight chroma. When FH-5 chroma increases gradually, the brightness of yellow sheet copper increases gradually, its chroma is when 4%~5% , brightness is the biggest. Continue to lift when the chroma of FH-5, of the metal corrode quickly, the brightness that creates brass appearance drops quickly. Accordingly, the concentration control of FH-5 is in 4%~5% is relatively appropriate. Nextpage5. The chroma of FH-6 of influence of FH-6 pH indicator is right brass the influence curve of weightlessness and a reflectivity is shown at graph 2-22. See by graph 2-22, on one hand FH-6 has delay corrode effect, PH indicator of the FH-6 in following polishing fluid increases, metallic weightlessness is reduced gradually. On the other hand, FH-6 has effect of add lustre to again, its chroma is 0. 15g/L~0.
When 20g/L, brightness is highest. These two kinds of action of FH-6 but what end restrained metallic matrix for the adsorption in metallic surface is fast and deliquescent, avoided metallic surface to cross cankerous happening. When FH-6 content is inferior, as a result of cannot surface of metal of complete Xiao Gai, affected the play of its delay corrode and action of add lustre to. Be in when content 0.
When 15g/L above, its adsorptive oneself in brass surface is saturated, make the brightness of metallic surface tends stability is worth. 2, the influence of polishing craft parameter to polishing effect 1. The influence polish temperature of polishing temperature is right brass the curve of weightlessness and a reflectivity is shown at graph 2-23. The result makes clear: The rate that the metabolic curve that metallic weightlessness follows temperature is a model one temperature curve, namely as temperature elevatory, deliquescent rate of the metal increases gradually. Temperature is too low, deliquescent quantity of the metal is little, the viscosity of polishing fluid is low, form mucus film not easily, polishing effect is poor; Temperature is too high, the viscosity of polishing fluid drops, easy create metallic appearance corrode too, brightness drops quickly. Accordingly, polishing temperature with 25 ℃ - between 35 ℃ advisable. 2. The influence polish time of polishing time is right brass the influence curve of weightlessness and a reflectivity is shown at graph 2-24. See by graph 2-24, in the begining, along with the extension of polishing time, weightlessness quantity of the metal increases quickly. When 3min~4min, weightlessness curve close to a platform, and platform is in corresponding yellow sheet copper have the biggest brightness. Because,this is right now polishing rate by diffusion control, achieved namely diffuse evenly. Continue to lengthen when polishing time, weightlessness quantity of the metal increases quickly again, easy generation is corroded too, the brightness of brass surface is reduced greatly. So, general polish 3min~4min can. 3, the blank that condition of optimal polish craft plays polishing effect is brass piece with polishing brass piece reflectivity test is shown as a result at graph 2-25. See by graph 2-25, the reflectivity of the yellow sheet copper after classics polish is as high as 86% , this shows this chemical polish craft has favorable polishing effect. In the meantime, in this polish recipe, the content of nitric acid is in 4% the left and right sides, and additive FH-6 has certain curb mist effect, accordingly, in oxide of the nitrogen in polishing process give off few. 4, conclusion (1) the optimal craft of polish of chemistry of brass low nitric acid is: 37% vitriolic, 4% nitric acid, 55% water, 4%FH-5 and 0.
15g/L FH-6, polishing temperature 30 ℃ , time 4min. (2) the reflectivity of brass surface after the polish below afore-mentioned optimal craft conditions is amounted to 86% . (3) the chroma of the nitric acid in polishing fluid is only 4% , and be below the curb mist action of FH-6, make the azotic oxide of generation few. CNC Milling
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