INFLUENCING FACTORS ON ETCHING RATES OF IRON NICKEL ALLOY FOILS IN FERRIC CHLORIDE SOLUTION

Several factors affecting the etching rates of Fex(x=56~59)Ni1-x alloy foils in FeCl3 etchant were studied with an immersion etching method.Especially,the quantity of Fex(x=56-59)Ni1-x alloy foils being dissolved in FeCl3 etchant,regeneration of spent etchants and replacement of nickel ions in FeCl3 waste etchants were also studied.The redox potential of etchants increased with increasing etchant concentration.The higher the redox potential,the bigger the etching trend.And the etching rate increased at first and then decreased with increasing concentration.The max of rate appeared when the concentration was about 40%.Etching rate increased with increasing temperature and decreasing pH.