Cause and Effect – Process Control 原因与结果—工艺控制
Properties throwing power brightness distribution of brightness ductility adherence/blistering deposition rate current efficiency chromatability Relations Influences carrier (SurTec 704 I) brightener (SurTec 704 II) zinc concentration NaOH or KOH content carbonate concentration foreign metals (iron, lead) current density temperature agitation
Anodes
电流分布更佳 节省能源 降低添加剂消耗量
Design of the Anodes
back side 背面
front side 正面
faced to the parts (cathode) 面向阴极 Gas evolution 气挥发方向
expanded metal ribs- Ni plated steel Flow of the gas evolution when anodes are correctly installed
现有中性盐雾测试规范 8微米镀锌+3价铬钝化 +封孔剂
汽车厂 GM 通用 3044 蓝白/黑色 五彩 白锈 红锈 热处理 热处理条件
120 120
240 360
或许需要 “ ” “
150 / 1hr
Ford 福特 WSS-M21P17 B1/B3 蓝白/银白色 96 ‘’ ‘’ 72 Daimler Chrysler克莱斯勒 PS 1207-R 吊镀 120 滚镀 100
温度 （度） 60 60 60 60 60 100 25 25
酸碱 值 2.0 2.0 2.5 2.5 2.5 2.0
膜厚（纳米） 300 - 350 420 215 300 415 460 70 300 - 350
* Av. Measured by : SEM, GDOES, Ellipsometry
欧洲对于现有汽车废弃的指导
到西元2006前，每辆汽车的回收使用率必须 达到其重量的85% 回收配件不得含有害及有毒物质 西元2007年7月1日起, 每辆新车不得含六价 铬
*美国实行现况*
GMW 3059 –2003年1月1号起，外销汽车及 配件不得含有六价铬 GMW 3044 – 2000年2月新制图不得含六价铬 GME 00252 –1998年5月新制制图不得含六价 铬 Chrysler – 2002年7月1号起新车型不得含六 价铬 Ford – 2000年1月新制图不得含六价铬
Zinc Anode Polarizes
锌阳极板极化后
Black smut 发黑
Alternatives to Zinc Anodes 可选用的锌阳极 Steel anodes 钢铁阳极 Inert anodes 惰性阳极 Catalyzed inert anodes 催化剂处理过的惰性阳极
Design of the Anodes
ROW NW. R (X) D 3 3.98 147 7.42
New Non Cyanide Zinc Process SurTec 704 average layer thickness: 3.7 µm lowest value: 2.4 µm highest value: 7.7 µm variation coefficient: 28 %
interference chemical parameter
physical parameter
ZincOperator
Sur Tec
Plan of the Strähle Galvanic Sy
SurTec 碱性非氰镀镀锌概念包含:
ROW NW. R (X) D 3 6.19 158 11.2
Low Cyanide Zinc Process 碱性低氰锌 SurTec 728 average layer thickness: 4.0 µm lowest value: 1.3 µm highest value: 8.8 µm variation coefficient: 48 %
ROW NW. R (X) D 3 3.58 70.7 4.97
碱性非氰锌
Electrolyte
Anodic Behavior Control of Zinc in the bath 镀槽中锌含量的控制
Using Zinc Anodes – Initial Conditions 开始使用时的锌阳极板
Acid Chloride Zinc 酸性锌
High efficiency- Fast plating rate 速度快 Good brightness – Decorative 光泽度好， 装饰性强 Uneven plate distribution 金属分布较不均匀 Poor throw in recesses and internal surfaces 对孔洞的深镀能力差 Corrosion of internal surfaces and LCD 内层深凹处及低电流区易腐蚀 Brittle deposits over 12 microns 膜厚超过12微米以上易脆裂
Most common problems in alkaline cyanide free zinc processes 一般碱性非氰镀锌工艺的问题
Poor plate distribution Difficult control of zinc content in bath 控制 Difficult control of additives Delayed blistering and poor adhesion 泡 Uneven passivation
Alkaline Cyanide Free Zinc 碱性非氰锌
Newer types are increasing in popularity. 渐受重视的新型工艺 Lower efficiency than ACZ – Slower. 电镀效率及速度较酸性锌低及慢 Good plate distribution. 金属分布能力佳 Semi bright to bright. 光泽介于半光至全光之间 Difficult to plate on high carbon steels and cast iron. 难以镀于高碳钢和铸铁
Oldest technology 最传统的技术 Low efficiency – Slow plating rate 电镀速度慢， 效率低 Good plate distribution 金属分布性好 Semi bright deposits 半光泽镀层 Environmental and safety issues 环保及安全考量 Being phased out. 逐渐被淘汰中
镀镍多孔网
Anodes
Supplying Zinc to the Bath 补充锌至镀槽
External zinc generators are used to dissolve zinc chemically and supply it to plating tank. 外挂式锌发生器用化学方式溶解锌并补充至镀槽
金属分布差 槽液中的锌含量难以
添加剂难以控制 附着力差, 延迟性起
钝化膜层不均匀
SurTec 704
Metal Distribution 金属分布
Comparison of Throwing Power at Hull Cell Panels 霍尔槽试片深镀能力的比较
Chloride Zinc Process 酸性锌 SurTec 758 average layer thickness: 6.5 µm lowest value: 1.4 µm highest value: 14.7 µm variation coefficient: 57 %
关心环保
New Developments in Zinc Plating 镀锌的新发展
SurTec 704 A total concept in alkaline cyanide – free zinc plating SurTec 704 -- 碱性非氰镀锌的整体概念
Alkaline Cyanide Process 碱性氰化镀锌
阳极的设计
•Replace zinc anodes in the tank. 更换镀槽中的锌阳极板 •Optional additional SurTec catalytic coating 可选择再涂以SurTec 催化剂涂层新型多孔金属网阳极. Advantages 优点: • better current distribution • lower cell voltage (energy savings) • lower consumption of additives
* 钝化膜厚 *
剖面放大四万倍
Supplying Zinc to the Bath 补充锌至镀槽
Conventional zinc generators with steel baskets are too slow. 传统的铁篮式锌发生器溶锌速度过慢 SurTec Hydrogen Catalysts coated baskets provide faster continuous zinc dissolution. SurTec 催化剂处理过的篮可使溶解速度更快
384 360
不需要 需要
120C / 4hrs
-
或许需要