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发表于 2012-4-20 23:23:54
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本帖最后由 dhzhou888 于 2012-4-20 23:30 编辑
铝合金的阳极氧化一般都要封闭(也叫封孔),只有对于主要使用功能是获得最大耐磨抗磨性的III类氧化膜,不应封闭。I,IB,IC,II和IIB类 除非合同,订购单与适用图纸另有规定,所有I、IB 、IC 、II和IIB类阳极氧化膜都应完全封闭。应该按照3.8.1.1或3.8.1.2来封闭。如果使用润湿剂,则需选择非离子型。
下面是美国军用标准对封闭的规定:
3.8 Sealing.
3.8.1 Types I, IB, IC, II, and IIB. All Types I, IB, IC, II and IIB anodic coatings shall be completely sealed, unless otherwise specified in the contract, purchase order or applicable drawing (see 6.2). They shall be sealed in accordance with 3.8.1.1 or 3.8.1.2, as applicable. If wetting agents are used they shall be of the non-ionic type.
3.8.1.1 Class 1. When class 1 is specified, sealing shall be accomplished by immersion in a sealing medium such as a 5 percent aqueous solution of sodium or potassium dichromate (pH 5.0 to 6.0) for 15 minutes at 90 deg. C to 100 deg.C (194 deg. F to 212 deg. F), in boiling deionized water, cobalt or nickel acetate, or other suitable chemical solutions (see 6.15).
3.8.1.2 Class 2. When class 2 is specified, sealing shall be accomplished after dyeing by immersion in a sealing medium, such as a hot aqueous solution containing 0.5 percent nickel or cobalt acetate (pH 5.5 to 5.8), boiling deionized water, duplex sealing with hot aqueous solutions of nickel acetate and sodium dichromate (see 6.11), or other suitable chemical solutions.
3.8.2 Type III. Type III coatings shall not be sealed where the main function of application is to obtain the maximum degree of abrasion or wear resistance. Where Type III coatings are used for exterior non-maintained applications requiring corrosion resistance but permitting reduced abrasion resistance, the contract or purchase order shall specify that sealing is required. Sealing for such Type III coatings shall be accomplished by immersion in a medium, such as boiling deionized water, in a hot aqueous 5 percent sodium dichromate solution,in a hot aqueous solution containing nickel or cobalt acetate or other suitable
chemical solutions (see 6.2). When Type III coatings are provided unsealed,parts shall be thoroughly rinsed in cold, clean water and dried after anodizing. |
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