鋁(lv)板產(chan)品被廣泛應用(yong)于(yu)汽車、建(jian)筑(zhu)等(deng)行業，提(ti)高鋁(lv)產(chan)品的質量是(shi)企業生存的根本(ben)所(suo)在，鋁(lv)質材(cai)料(liao)在空氣中(zhong)是(shi)極不穩定的，容易生成(cheng)(cheng)用(yong)肉眼也(ye)難以識別(bie)的氧化膜(mo)。由(you)(you)于(yu)鋁(lv)件(jian)加工(gong)(gong)(gong)工(gong)(gong)(gong)藝方法的不同(tong)，如(ru)鑄造成(cheng)(cheng)型(xing)(xing)，或(huo)是(shi)由(you)(you)延壓(ya)板材(cai)直接剪切而成(cheng)(cheng)，或(huo)是(shi)機械精(jing)細(xi)加工(gong)(gong)(gong)成(cheng)(cheng)型(xing)(xing)，或(huo)是(shi)經不同(tong)工(gong)(gong)(gong)藝成(cheng)(cheng)型(xing)(xing)后(hou)又經熱處理(li)或(huo)焊接等(deng)，工(gong)(gong)(gong)件(jian)表面(mian)(mian)都會呈現不同(tong)狀態(tai)，不同(tong)程度的污物或(huo)痕跡，為此在前處理(li)工(gong)(gong)(gong)序中(zhong)必(bi)須根據工(gong)(gong)(gong)件(jian)表面(mian)(mian)的實際情況選擇前處理(li)的工(gong)(gong)(gong)藝方法。

預處理工(gong)藝中需要注意，鑄造成型件并(bing)非(fei)所有(you)(you)表面(mian)(mian)都經(jing)過(guo)(guo)機械加(jia)(jia)(jia)工(gong)，未經(jing)機加(jia)(jia)(jia)工(gong)的表面(mian)(mian)留有(you)(you)澆鑄過(guo)(guo)程(cheng)中形成的過(guo)(guo)厚氧化(hua)(hua)層，有(you)(you)的還(huan)夾有(you)(you)砂(sha)層，此時應先用機加(jia)(jia)(jia)工(gong)或噴砂(sha)方法先除去(qu)這(zhe)(zhe)一部(bu)位的原始氧化(hua)(hua)膜(mo)，或是經(jing)堿洗后再加(jia)(jia)(jia)工(gong)，只有(you)(you)這(zhe)(zhe)樣才能既(ji)除凈未加(jia)(jia)(jia)工(gong)部(bu)位的原始氧化(hua)(hua)層，又可避免機加(jia)(jia)(jia)工(gong)部(bu)位公(gong)差尺(chi)寸的改變。

精(jing)細加工件(jian)(jian)(jian)在前處理工序中需要注意(yi)的問題：精(jing)細加工件(jian)(jian)(jian)雖(sui)然表(biao)面的自然氧化膜才(cai)初生成，較易清(qing)除(chu)，但油(you)(you)膩重(zhong)，特(te)別(bie)是孔(kong)眼內(nei)及其周圍，這類工件(jian)(jian)(jian)必(bi)須先經有(you)機(ji)溶劑(ji)清(qing)洗，若(ruo)直接用堿(jian)洗不(bu)但油(you)(you)膩重(zhong)難以除(chu)凈，且精(jing)細加工面承受不(bu)了(le)長時間的強堿(jian)腐蝕，結果還會影響(xiang)到工件(jian)(jian)(jian)表(biao)面的粗糙程度和公差的配合(he)，最(zui)終(zhong)有(you)可(ke)能成為廢品。