Aluminium Surface Modification
Technical University of Denmark, Kgs. Lyngby,
8th November 2006
Aluminium with its unique properties is able to provide intelligent, imaginative, effective and above all, sustainable solutions to all manner of modern-day needs. The aluminium industry is already one of Europe’s foremost employers, directly providing in excess of 255,000 jobs. In order to widen the market especially in architecture, packaging, and automotive, European Aluminium Association has launched an European Aluminium Technology Platform VISION 2030 (EATP 2030) in 2006. Surface modification is an important issue in increasing the usage of aluminium alloys. This includes Chrome free surface treatments, Anodization processes, and modification of aluminium surfaces for novel properties such as Self-clean, anti-bacterial, and non-wetting. However, there are several challenges ahead in many of these areas.The seminar will focus on following aspects:
- Aluminium alloys: Microstructure and Properties
- Chrome free surface treatment for aluminium alloys
- Aluminium surface protection and modification
- Surface modification of aluminium for novel properties
Who should attend:
- Materials Engineers
- Technology forecasters on aluminium
- Corrosion engineers and specilists
- Researchers and academics
PROGRAMME:
| 09:00 - 09:30 | Arrival and registration |
09:30 – 09:40 |
Welcome and Introduction to the seminar |
| Microstructure and corrosion of aluminium alloys | |
09:40 – 10:10 |
Microstructural effects in corrosion of aluminium alloys Rajan Ambat, Associate Professor, IPL, DTU Corrosion sensitivity of metallic alloys is dictated by the microstructural heterogeneity at the surface and their galvanic interaction. The heterogeneities could be second phase particles, localized variation in solid solution composition, grain boundary precipitates, formation of precipitate free zones (PFZ) etc. In aluminum alloys corrosion sensitive microstructures with above features could form in the weld zone during joining process such as friction stir welding and spot-welding, and at the surface of rolled sheets due to enhanced surface deformation. Present talk focuses on the relation between microstructure and corrosion/electrochemical behaviour in 2xxx, 5xxx and 3xxx series Al alloys which is either friction stir welded, spot-welded or rolled. Talk also focus on the application of micro electrochemical technique for corrosion evaluation of welds which enables one to do corrosion measurement down to micrometer scale. |
10:10 - 10:40 |
Impurity tolerance and low cost route for aluminium sheet production Geoff Scamans, Principal Scientist, Innoval Technology, UK Aluminium scrap, that can be perpetually recycled, will become more and more available from transport and architectural applications particularly as tougher landfill and end of vehicle life legislation comes into force. The main issues are impurity tolerance and the use of production routes that minimise conversion costs. The corrosion properties of block cast AA6011 sheet made from secondary metal have been studied as part of an EU funded project and presently high iron (up to 0.4 wt%) AA5754 sheet made from melts subjected to high levels of shear and turbulence prior to casting is being evaluated. The prospects for the production of high performance and durability aluminium automotive sheet from recycled metal will be discussed. (reduced abstract - Read full abstract). |
10:40- 11:00 |
Coffee break |
| Chrome free surface treatments for aluminium alloys | |
11:00 -11:30 |
Probing nano organic molecular interactions on Al oxide surfaces Herman Terryn, Professor, VUB Brussels In this presentation the interaction between organic molecules and metal oxides (Fe and Al) is considered. The overall study concentrates on the chemical interface, created between an organic layer and a metal oxide layer. The knowledge of the composition and structure of thin metal oxide surface layer is important for the bonding between metals and polymers. For obtaining this information a complementary approach is sued based on a number of surface analysis methods given different type of information. In a first part the structure, composition and thickness of the oxide Fe and Al layers is related with the surface optical and electrical properties. As roughness is important polished metal surafces samples were used. FESEM, FEAUGER, AFM and XPS were used to see the distribution and amount of the organic molecule present over the surface. An approach is given to verify to what extend a monolayer is formed. Thickness estimations can be obtained by Spectrocopic Ellipsometetry. XPS and FTIR-RAIRS were used to study the nature of the interfacial bonding. Data were obtained about phosphonic acids, carboxylic acids, esters and benzohydroxamic acids. It will be shown that the aluminium surface pretreatment has an influence on the amount of organic molecules that are interacting with the aluminium surface. |
11:30 – 12:00 |
Silane pretreatments of aluminium Iris De Graeve, Dr., VUB Brussels Silane coating is an environmentally sound surface pretreatment of metals, including aluminium, steel and galvanised steel. Good corrosion performance has been assigned to these hybrid organic-inorganic thin film deposition systems (< 1µm). The silane molecules contain -Si-O-CnH(2n+1) groups, which after hydrolysis in solution into silanol groups -Si-OH can form covalent bonded layers on the metal surface; condensation reactions between silanol groups and metal hydroxide groups (M-OH) lead to the formation of a –Si-O-M bonded interface. Curing is considered essential for corrosion protection, as the barrier properties improve with crosslink density; during heat treatment condensation reactions between silanol groups in the film result in -Si-O-Si- network formation. Various silane systems have been investigated in the VUB research group, including BTSE, BAS and APS, on aluminium, steel and galvanised steel substrates. This contribution gives an overview of the combined research efforts, mainly on BTSE. A chemical and morphological characterisation of silane films as function of the film forming parameters is presented. The effects of the silane solution (concentration, hydrolysis & condensation reactions), the process time, the film formation mechanism and curing of the film are discussed. |
12:00 – 13:00 |
Lunch Break |
| Anodising and Painting of aluminium | |
13:00 – 13:30 |
Corrosion of painted aluminium Andreas Afseth, Senior Scientist, Novelis Technlogy, Swizterland Over the past ten years a detailed understanding of the dominant factors controlling the corrosion susceptibility of painted aluminium alloy sheet used for architectural and automotive applications has been developed. Work carried out in this field will be reviewed and the different modes of cosmetic corrosion that can occur-, the mechanisms of surface activation, and the role of different thermo-mechanical processing steps on controlling corrosion susceptibility for different alloy systems, including Al-Mn, Al-Mg and Al-Mg-Si-(Cu) will be discussed. The critical role of chemical or electro-chemical cleaning prior to pre-treatment and coating will be highlighted and prospects for meaningful accelerated testing will be discussed. |
13:30 – 14:00 |
Adhesion of organic coatings on modified chromate-free aluminium surface Kemal Nisancioglu, Professor, NTNU, Norway. The development and use of new conversion coatings brought to the fore the need for quantitative test methods and a reevaluation of the compatibility between the aluminum substrate, conversion coating and the organic paint because very few of the chromate-free alternatives have so far proven to be as robust as chromating. While reliable methods are available for corrosion testing, the standard tests for adhesion are not always adequate. The presentation will first discuss new quantitative methods for wet paint adhesion, based on fracture mechanical approach adopted from testing of adhesives. Based on these methods several conversion coating - paint combinations are evaluated for AA6082 aluminum alloy substrate, showing that these combinations have to be considered separately, and a clear universal alternative for chromating can be difficult to identify. Furthermore, incompatibility of common types of organic coatings with the aluminum surface are demonstrated based on the alkalinity of these coatings, which were originally developed for steel. The idea of using pigments which have the buffering capacity to ensure a more stable oxide film on the aluminum surface for improved adhesion is discussed. |
14:00 – 14:30 |
New challenges for anodized aluminium Ib Kongstad, Technology Specialist, Bang and Olufsen A/S, Denmark. Bang & Olufsen meets demands from costumers in audio-video and automotive sector. Solutions and possibilities are presented. A new patent from B&O - Innovation inspired by nature (Biomimicry). |
14:30 – 14:50 |
Coffee break |
| Hard and novel coatings on aluminium | |
14:50 – 15:20 |
Wear resistant coatings on aluminium alloys Per Møller, Professor, IPL, DTU. |
15:20 – 15:50 |
Comp-cote R coatings for aluminium alloys Hans Bohman, Business Development Manager, Bodycote Surface Engineering. Comp-CoteR is a new anodising like method for improved properties on Aluminum. It is a method, combining metalloxide and polymer, which enables the industry to improve the properties that are obtained through anodising. Comp-CoteR presents better wear-resistanse, better surface roughness, better corrosion resistance - more than normal anodising. The method, which is based on an american patent, has for 5 years been available to the industry performed by Bodycote in Europe. Hans Bohman, Sales Manager at Bodycote Surface Engineering in Sweden will make the presentation from a technical perspective. Hans Bohman, Sales Manager at Bodycote Ytbehandling AB in Sweden has been involved in the surface treatment business for the last 30 years. Mr Bohman has under the years occupied different responisibilitys such as, Production Manager, General Manager and Sales Manager. His experiences has always been connected to the european industry as a sub-supplier. He has for more than 20 years been involved in the The Swedish Electroplaters and Finishing Industry and is today a present Board member of the International Hard Anodising Association. |
15:50 – 16:00 |
Concluding Remarks |
Language: English.
Programme concept:
Rajan Ambat, ass. professor, IPL, DTU and Ib Kongstad, Technology Specialist Aluminium Surfaces, Bang & Olufsen A/S.
Organized by :
Light Metal Group/ATV•SEMAPP, Aluminium Danmark and Dansk Selskab for Materialeprøvning og -Forskning, DSM (Ingeniørforeningen i Danmark, IDA).
Venue/Place:
Auditorium 38, Bygning 306, Danmarks Tekniske Universitet, 2800 Kgs. Lyngby.
Klik her og se DTU-vejviser.
Fee:
Members of ATV-SEMAPP and Aluminium Danmark: DKK: 1750,- Others: DKK: 2350,- .
Members of DSM and IDA can find the price from IDA ( link below).
Registration:
Before friday the 27th October 2006 to the Reception, IPL, IPU and ATV-SEMAPP, phone +45 45 25 48 00, att. Grethe Lund Rasmussen / Michael Jensen, or to Erling D. Mortensen, tlf. 45 25 46 30, E-mail: semapp@ipl.dtu.dk , fax 45 93 45 70. Later registration is possible if room is available.
Fill in Registration form/Tilmeldingsformular or
send name, occupation, affiliation, address, zipno./city, phone no. of affiliation organisation and invoice address.
Ask for membership if wanted.
Members of DSM and IDA may use the meeting-registration at IDA (Arrangementsnr.: 62357).