不銹鋼化學著色配方 20 (見表8-9) ,本配方(fang)由沈陽(yang)工業學院金光、張學萍、畢監智于2004年提出。
他們通過正交試驗研究了不銹鋼著(zhu)色液配方、溫度、時間、電極電位對著色的影響,優化著色工藝,獲得電極電位與顏色的良好對應關系,測試了著色膜的耐磨性,耐蝕性、變形加工性能,分析添加劑對不銹鋼著色的影響。所得膜層顏色均勻,耐磨性、耐蝕性、變形加工性能良好,工藝維護簡單。
1. 實驗工(gong)藝(yi)流(liu)程
304不銹鋼(gang)(鏡面光亮8K)→清洗→堿性除油→水洗→酸活化→著色→硬化(鉻酐250g/L,濃硫酸1.4mL/L,DK0.5~1.0A/d㎡,溫度45~55℃,時間10~15min)→水洗→封閉(Na2SiO3 10g/L,溫度沸騰,時間10~15min)→水洗→干燥。
2. 實(shi)驗結果
①. 溫度
50℃時加(jia)入較多添加(jia)劑,反應(ying)速率平穩,著(zhu)色(se)膜色(se)澤(ze)均勻,鮮艷(yan)度好。
60℃時添(tian)加劑含量對結果(guo)影響不大,膜層質量好。
100℃時(shi)溫(wen)度高,使反(fan)應速率過(guo)快,著(zhu)色膜色澤不(bu)均勻,不(bu)易控制。
②. 表面膜的(de)電極電位與(yu)顏色的(de)對應關系
著(zhu)(zhu)色時(shi),開始電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)很高,而后迅速下降(jiang),之后逐步上(shang)升,到達一個高點電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)后再下降(jiang)。這個高點電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)為著(zhu)(zhu)上(shang)顏(yan)色的(de)(de)(de)起(qi)始電(dian)(dian)(dian)(dian)(dian)(dian)極電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)。圖8-22為不銹(xiu)鋼片對鉑片的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)極電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)與時(shi)間的(de)(de)(de)關(guan)系(xi)曲線。著(zhu)(zhu)色時(shi),每隔1min用(yong)數(shu)字(zi)萬用(yong)表記錄(lu)下不銹(xiu)鋼片對鉑片的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)極電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei),著(zhu)(zhu)色時(shi)間5min,199mV,變(bian)成黑色的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)是(shi)(shi)189mV,變(bian)成藍色的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)是(shi)(shi)187mV,變(bian)成黃色的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)是(shi)(shi)185mV,變(bian)成金黃色的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)是(shi)(shi)183mV,所以,黑色的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)差(cha)是(shi)(shi)10mV,藍色的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)差(cha)是(shi)(shi)12mV,黃色的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)差(cha)是(shi)(shi)14mV,金黃色的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)(wei)(wei)差(cha)是(shi)(shi)16mV。
③. 前(qian)處理對著色的影響
化學除油時,著(zhu)(zhu)色面應充分被水(shui)所潤濕,否則結合力欠佳(jia)或發花,甚至著(zhu)(zhu)不上色。
活(huo)化(hua)(hua)是為了消除(chu)不銹鋼表面的鈍化(hua)(hua)膜(mo),獲(huo)得(de)新鮮表面。活(huo)化(hua)(hua)不足,著色(se)的起始電位保持時間(jian)長(chang),顏色(se)不容易(yi)控制,活(huo)化(hua)(hua)過度則使著色(se)膜(mo)暗淡無(wu)光。
④. 后處理的影響
著(zhu)色(se)(se)膜形成后存在(zai)大量微細(xi)孔,腹層疏(shu)松不牢固(gu),易磨損(sun),必(bi)須硬化(hua)處(chu)理。硬化(hua)處(chu)理后防止(zhi)表面被污染,需(xu)封(feng)(feng)閉處(chu)理。封(feng)(feng)閉煮沸時間(jian)以15~20min為佳(jia)。時間(jian)過(guo)短,耐磨性不佳(jia),過(guo)長形成色(se)(se)斑,顏色(se)(se)深度下降。
⑤. 添加劑的影(ying)響
適當(dang)加入少量鉬酸(suan)銨有利于(yu)封閉后著色(se)(se)膜的(de)耐磨(mo)性(xing)提高,會加速(su)(su)著色(se)(se)膜中微孔的(de)充(chong)填效果。碳酸(suan)鹽和硫酸(suan)鹽加快著色(se)(se)速(su)(su)率。
⑥. 攪拌(ban)的影響
攪拌著色液的著色膜色彩均(jun)勻性明顯(xian)優于不攪拌的著色液。
3. 著色膜(mo)層性能實驗(yan)
①. 耐蝕(shi)性(xing)
著(zhu)色(se)試片放入(ru)20%硫(liu)酸中,48小時未(wei)發生腐蝕。未(wei)著(zhu)色(se)試片很快被腐蝕。
②. 耐(nai)磨性
用(yong)橡皮反復擦拭著色面300次,沒有發現起皮現象(xiang),說(shuo)明耐磨(mo)性很好(hao)。
③. 加工性能(neng)
彎曲(qu)180°,著色膜沒有(you)脫(tuo)落。說明具有(you)良好的機械(xie)加工性(xing)能。