QUALANOD. QUALISINO AGM, Foshan, 27-28/10/2015. Anodizing and sealing process. Riccardo Boi QUALICOAT Technical Director

Transcription

1 QUALANOD QUALISINO AGM, Foshan, 27-28/10/2015 Anodizing and sealing process Riccardo Boi QUALICOAT Technical Director

2 PREMISE QUALANOD specifications are based on european experiences and technologies eveloped mainly for architectural market (see old specifications CIDA) 欧盟的建筑行业的标准 ( 老标准 CIDA) QUALANOD foundation is dated on 1974 by the european association of extruder (EWAA) and of anodizers (EURAS).1974 年有 EWAA 和 EURAS 成立 The main reason was to increase to confidence to this new technologies in the market of the finishing, not only to create a quality label «QUALANOD» but also increasing the number of researches and testing programs. In that period a lot of extruders laboratories were involved to study the new technology. 不仅是为了建立一个标准而是为了提高该工艺的市场应用和信心 当时有很多挤压厂以及实验室参与该标准的研究与定制

3 PREMISE (See The Results Of Exposure Tests In Different Sites For Twenty Years Cida) All these results were the base for ISO standard and for the testing method. 很多测试是基于 ISO 标准进行

4 New requirements for anodizing plants 氧化厂的要求 The specifications need a special care with reference not only to the new technologyes or new testing, but also to the ambient and safety. 不仅仅是工艺和测试, 还对环境和安全提出要求 Just few years ago QUALANOD decided to open the specifications to the other activities where the anodic coating is used, hard anodic coating or reflective surface. there is a wg in qualanod that is studying all this matter and a new specifications must contain all these news. 硬质氧化以及高光反射表面也被研究, 新的标准也会包含此内容 I D LIKE TO SHOW ALL THE NEW UPDATES GIVING YOU MORE TECHNICAL DETAILS AT THE BASIS OF THE DECISION.

5 New requirements for anodizing plants 更新 Update Sheet No. 1 (revised Appendix VI Assessement of New Products and Processes) 新产品工艺的认证 Update Sheet No. 2 (new appendix VIII Continuous Coil Anodizing) 连续卷铝氧化 Update Sheet No. 3 (Light fastness) 耐色牢度 Update Sheet No. 4 (Solutions for sealing test) 封孔测试 Update Sheet No 5 (Negative results of abrasion test) 耐磨性能测试 Update Sheet No 6 (Explicit definition of sealing processes requiring an approval) 需要认证的封孔工艺 Update Sheet No 7 (Specification of etching practices) 蚀刻要求 Update Sheet No 8 (Rules for the use of the logo by third parties) 第三方使用标志的要求

6 Update Sheet No. 1 (revised Appendix VI Assessment of New Products and Processes) This update give a procedure to introduce the new technologies in the specifications. Not only referring to the anodizing process conditions, like the new sealing products or the additives for sulfuric acid, but including big change like coil anodizing, as we can see in the next slides. 新工艺的认可不仅仅是新的封孔剂认证, 还包含了连续卷铝氧化等内容

7 Update Sheet No. 1 (revised Appendix VI Assessment of New Products and Processes) The Specifications define closely the procedures to be adopted by licensed anodizers. Inspectors ensure that these procedures are being followed. If an anodizer wishes to use a new process or product he should find out from QUALANOD whether it has been previously assessed. If not then he should apply to QUALANOD to have the process or product assessed. This would also apply if a supplier wishes to offer a new process or product for licensed anodizers to use. The results of the assessment will be evaluated by the QUALANOD Technical Committee. If it decides that the assessment has been successful, then it will recommend to the Executive Committee that, as appropriate, an addendum to the Specifications should be introduced and the Inspectors should be instructed on new inspection requirements. The applicant will be notified of decisions of the Executive Committee. 任何氧化厂需要使用新工艺都必须首先获得 QUALANOD 技术委员会的认可, 执行委员会将会通知氧化厂新工艺的批准情况

8 Update Sheet No. 2 (new appendix VIII Continuous Coil Anodizing) The process conditions and technologies are significantly different from the normal batch anodizing where discrete lengths of aluminium extrusion or sheet or small components such as castings are fixed to racks which are then transported by a crane and lowered sequentially into the different processing baths. These conditions give the possibility to anodize faster than normal batch anodizing. Generally the strip is passed through the line at such a speed that anodizing has to be carried out more rapidly than in batch anodizing. 与普通的氧化不同, 连续卷铝氧化速度更快

9 Update Sheet No. 2 (new appendix VIII Continuous Coil Anodizing) Continuous coil anodizing can produce a product equivalent to that produced by batch anodizing. However, there are significant differences. Particular process control must be applied to produce a good quality product by continuous coil anodizing. Thus certain inter-related process parameters must be closely controlled and ensured to be uniform across the width of the strip. 可以生产与批次氧化相类似的产品, 但是相关的工艺参数要进行严格控制来确保产品质量的均匀性 Heat dissipation is effected by the differential movement of the strip and counter-flowed anodizing acid which is recirculated through a heat exchanger. Thus air agitation of the acid generally becomes unnecessary. Poor heat dissipation can lead to excessive attack of the anodic coating surface by the acid depending on the acid concentration. The coating becomes more porous and softer. It is known that anodic coatings with such characteristics can exhibit performance deficiencies during weathering. The strip speed determines the contact time in the anodizing solution and thus the current density should be adjusted to achieve the required anodic coating thickness. But high current density causes local heating of the acid, which then should be dissipated into the acid. Clearly, different combinations of the four parameters can be chosen that would give the required anodic coating thickness without producing an unacceptably soft coating. The product tests of in-house control should be used to ensure that the chosen continuous coil anodizing conditions are producing the correct product quality. 通过热交换器来进行散热

10 The difficulties for anodizing in a standard plant using high current density, burning fenomena (see defects), obliged the laboratory to study new technologies. The best results were otained using liquid contact. How

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12 Why we can say that the layer of anodic coating are the same properties indipendently by the different anodizing conditions? The different conditions are the following:

13 Sulphuric acid electrolytes STANDARD ANODIZING CONDITIONS H2SO4 concentration should be not more than 200 g/l ;. Aluminium content should be not more than 20 g/l but preferably within 5 to 15 g/l. The chloride content should be not more than 100 mg/l. Current density: not more than 2 A/dm² (in function of the thickness) Temperature: 20 C Sulphuric acid electrolytes COIL ANODIZING CONDITIONS H2SO4 concentration should be not less than 25% (290 g/l); Current density: more than 6-10 A/dm² Temperature: >= 30 C

14 DIFFERENT ANODIZING CONDITIONS How we can determine the quality of the anodic layer? The parameters used in the past in the laboraotry were the following: Coating Ratio (CR) and Unit Sealing Value (USV). 成膜率 These two parameters in the past were used to defined the quality of anodic layer. What means Coatig Ratio? And Unit Sealing Value? Unit Sealing Value is strictly linked to hot sealing and for this reason USV is not valid for our evaluation

15 Coating Ratio represents the weight of the anodic coating divided by the weight of aluminium reacting (the last being the combined weight of metal converted into oxide plus that going into solution). Assuming that the coating is composed entirely of Al2 0 3, the coating ratio has a theoretical maximum of In practice the anodic coatings nearly always contain some of the solution anion. In the case of sulphuric acid anodizing on 99.95% aluminium, approximately 12-14% S03 (calculated from sulphate determination) is found in the coating which gives a maximum coating ratio of approximately 2.2.

16 Examples: P1 = Weight before to anodise 氧化前质量 P2 = Weight after anodise 氧化后质量 P3 = Weight after Deoxidation 脱脂以后的质量 Panel dimensions: 50x100 mm = 1 dm² (2 mm thick) Alloy AA6060 P1 = 24,2726 gr P2 = 24,3173 gr P3= 24,1821gr CR =(P2-P3) (24, ,1821)/(P1-P3)(24, ,1821) = 130,5/90,5 = 1,49

17 COATING RATIO DEFINITION Decrease of coating ratio is approximateiy linear with time at constant current density. The voltage rises as the coating thickness increases, and this reflects increasing dissolution of the coating during its growth associated both with a Iarger active surface area with progressive dissolution in the pores and increase in the Iocal temperature due to the higher voltage required as the coating grows in thickness.

18 Coating Ratio for various alloys

19 However it is the principle of liquid contact anodizing which has allowed significant developments in continuous anodizing. Current flows from the positive output of the power supply to the anode in the first electrolyte and, upon entering the solution, the usual anode reactions occur; in this case oxygen is evolved. The strip in this solution is cathodic with respect to the anode and therefore cathodic reactions will occur; in this case hydrogen is generated. The current then travels along the length of the aluminium strip until it enters the second solution where the strip is anodic relative to the cathode in this electrolyte. Anodizing of the aluminium therefore occurs in this bath and hydrogen is evolved at the cathode. The strip is bipolar, in that it is cathodic in the first section and anodic in the second, and this method of anodizing is sometimes called the 'bipolar electrode' method.

20 Current density 电流密度 For sulphuric acid-based anodizing, the average current density should be: amp/dm² for class 5, amp/dm² for class amp/dm² for class 20, 25

21 Sealing by hydrothermal treatment 热封 Cold impregnation/cold sealing (CI-CS) based on nickel fluoride 冷封 First stage of treatment: impregnation Concentration of the CI-CS product: Nickel ion content g/l Ni 2+ 含量 Free fluoride ions g/l F - 含量 Second stage of treatment - ageing by hot water treatment To complete the CI-CS process, the treated parts should be exposed to high humidity for some time, which can be accelerated by immersing the cold sealed parts in a hot water bath according to for 0.8 to 1.2 min/µm or in a 5 to 10 g/l nickel sulphate solution at a minimum temperature of 60 C for min/µm. This makes the work easier to handle and check, and should be considered an essential part of the treatment. 冷封后热水陈华

22 Results of investigation on Abrasive paper and Cr6+ 耐磨砂纸和六价铬

23 Material for the abrasion resistance test Suitable glass coated paper, grade 00 very fine, for abrasion testing shall be available (see section 2.4.1). 00 级砂纸来进行耐摩性能测试

24 QUALANOD TC WG 3 RESULTS OF STUDIES TO DEVELOP A REFEREE TEST SAMPLES 研究发明一种仲裁测试样品 (R. Boi)

25 The testing programm carry out by a student is one of the the results of yearly cooperation between University of Novara and QUALITAL Laboratory.QUALITAL 与一些大学合作 Every year, QUALITAL offer the possibility for a student to investigate in some specific items related to aluminium finishing. 每年 QUALITAL 会提供一些机会给大学生来研究铝材表面处理的项目 I de like to remember that Novara was the center of research on aluminium, started in 1937 and definitevely closed few years ago 诺瓦拉从 1937 年开始就是意大利铝行业的研发中心 25

26 QUALITAL Pilot Plant All the samples for the tests were anodized in this pilot plant by student, followed by our technicians 试验实验室

27 Details of the samples preparation and anodizing bath Anodizing conditions: 氧化条件 H2SO4: 202 g/l Al: 7,9 g/l Temperature: Surface anodized: 12 dm² (3 samples of 100*200 mm) Current density: 1,5 A/dm² Total Ampere: 18 A Tickness: ca. 22 µm Time of anodizing: 48 minutes

28 5 SET OF SAMPLES FOR TESTING PROGRAMM CODE Surface preparation Anodizing T C Agitation Colouring Sealing A ü 20 ü ü ü B ü 24 ü ü ü C ü 26 ü ü ü D ü 20 no ü ü E ü 24 no ü ü

29 Roughness of samples

30 ABRASION TESTS To check abrasion resistance performance we used the following test 1) BS Determination of surface abrasion resistance (Clark test), BOTH METHODS 克拉克测试方法 1 和 2 Abrasive paper used: Norton Oakey Cabinet Quality Glasspaper - Grade 00, grit 240 Product code: The following lots: 砂纸的厂家, 批号等 ) Taber test ASTM D ,

31 Carte abrasive Carte abrasive fornite da: Hallmark Fraulo I riferimenti: Norton Oakey Cabinet Quality Glasspaper Grade 00, grit 240 Product code: Lotti di provenienza: , , 707

32 Surface abrasion test (Clark test) Abrasive paper used: Norton Oakey Cabinet Quality Glasspaper - Grade 00, grit 240 Product code: The following lots:

33 Sample A carta abrasiva Campione Prova Metodo 1 (10 doppie passate) Presenza polverino Spess. Iniziale ( µ m) Metodo 2 Variazione Spess. Finale ( µ di spessore m) ( µ m) Media Valutazione Max diff 2 µ m A 1 no 24,7 24,4 0,30 passato A 2 no 24,9 24,5 0,40 0,33 passato A 3 no 24,4 24,1 0,30 passato 2003 A 1 no 24,6 24,0 0,60 passato 2003 A 2 no 24,5 24,1 0,40 0,47 passato 2003 A 3 no 24,8 24,4 0,40 passato 2004 A 1 no 24,6 23,8 0,80 passato 2004 A 2 no 24,8 24,2 0,60 0,57 passato 2004 A 3 no 24,6 24,3 0,30 passato 707 A 1 no 24,4 23,9 0,50 passato 707 A 2 no 24,5 24,0 0,50 0,40 passato 707 A 3 no 24,7 24,5 0,20 passato Figura 16: campione "A" sottoposto alle prove Clark in cui sono visibili le tre serie effettuate. In nessuna prova si è asportato la colorazione superficiale

34 Sample B carta abrasiva Campione Prova Metodo 1 (10 doppie passate) Presenza polverino Spess. Iniziale ( µ m) Spess. Finale ( µ m) Metodo 2 Variazione di spessore ( µ m) Media Valutazione Max diff 2 µ m B 1 si 23,5 22,0 1,50 passato B 2 si 23,4 22,2 1,20 1,47 passato B 3 si 23,1 21,4 1,70 passato 2003 B 1 si 23,4 20,9 2,50 non passato 2003 B 2 si 23,6 21,2 2,40 2,17 non passato 2003 B 3 si 23,2 21,6 1,60 passato 2004 B 1 si 23,7 17,8 5,90 non passato 2004 B 2 si 23,4 20,0 3,40 4,43 non passato 2004 B 3 si 23,2 19,2 4,00 non passato 707 B 1 si 23,4 15,6 8,80 non passato 707 B 2 si 23,2 19,9 3,30 5,10 non passato 707 B 3 si 23,4 20,2 3,20 non passato Tabella 17: risultati relativi al test di Clark effettuato sul campione "B". A differenza del campione "A" si è in presenza di discreta quantità di polverino (metodo 1) per ogni tipo di carta utilizzata, mentre per quanto riguarda il metodo 2 i risultati variano in base alla carta abrasiva utilizzata: la carta supera mediamente il test a differenza delle altre utilizzate.

35 ASTM D: (riapprovata nel 2001) e consiste nel causare abrasione al rivestimento superficiale del campione fino al raggiungimento del metallo puro tramite caduta ciclica di sabbia, certificata (Ottawa), su di esso in un punto specifico, ogni ciclo prevede l utilizzo di 2 litri di sabbia ovvero 3162,3 grammi.

36 Cam pion e n Spes sore (µm) spess ore (mils) volum e sabbia (l)/cicli n di cicli volum e sabbia (l)/cicli n di cicli vol. sabbia totale (l) A=V/T (l/mils) A 24,5 0, , ,46 B 23,4 0, C 23,3 0, ,2 3 8,6 14, ,2 6 9,2 15,55

37 Taber test

38 Δmg Grafico 1: confronto della perdita di peso media parziale ad ogni 500 cicli di ogni campione (espressa in mg) 每 500 个循环每个样品的重量损失比较

39 Taber results every 500 cycles (Delta mg) CODE Anodizing T C Agitation A 20 Yes B 24 Yes C 26 Yes D 20 No E 24 No

40 Comparazione prova Taber e prova Clark Taber 测试结果和砂纸耐磨性能测试结果的比较

41 Grafico 3: confronto della perdita parziale di spessore dei campioni dopo ogni 100 cicli. 图 3: 样品的厚度损失各 100 次循环后的对比

42 Paper Abrasion results with 4 different lots CODE Anodizing T C Agitation A 20 Yes B 24 Yes C 26 Yes D 20 No E 24 No

43 The results of the studies showed claerly the influence of the abrasive paper on the final results, mainly in the intermediate field. Using a reference panel we are able to find the abrasive paper less perfomance The reference samples must be prepared in a laboratory following strictly procedure, as in annex. 结果表明砂纸质量的不同对最终结果有影响 特别是在中间过程 通过使用标准样板我们可以找出性能不太好的砂纸 但是标准样板需要严格按照流程来准备 Taber study could be used a reference test method, but it s important to better define the conditions of testing method (type of abrasive, weight, roughness). Taber 测试可以作为耐磨性能的仲裁测试, 但是需要明确定义测试方法的条件 ( 磨料的类型, 重量以及粗糙度 ) The influence of the thickness is an important factor not well considered. 膜厚也是影响耐磨性能的一个重要参数 我们这些研究中没有进行考察

44 STUDY ON ANODIC OXIDE COATING SEALING QUALITY ASSESSMENT METHODS FOR PHOSPHORIC/CHROMIC ACID IMMERSION TEST REPLACEMENT 失重测试方法的研究 Proposal for a new test specification 新测试方法 The study was carry out by LNEC (Portugaise Laboratory) in cooperation with other laboratories involved in QUALANOD to find a method ecxluding Chromium 6+ by the solution. LNEC 葡萄牙实验室主导无铬的失重测试 The results of these studies were quite interesting and QUALANOD decided to introduce the method in combination with the inspection opf the anodizers and starting from this year, only the method without Chromium was accepted by QUALANOD. Following there is the last updated sheet on this matter QUALANOD 决定今年开始使用无铬的硝酸预浸磷酸失重测试

45 DEFECTS ON SURFACE AFTER SURFACE TREATMENT COLLEGAMENTO FILE DEFECTS

46 LABORATORY LABORATORIO

47 NO CONFORMITIES NON CONFORMITA

48 Thank you for your attention and I m at your disposal for any further question you are interested to have more details. 谢谢您的关注