Science of Successfully Anodizing Die Cast Substrate

Article From:  Products Finishing, Larry Chesterfield from Anodizing Technologies and Jude Mary Runge, Ph.D., Principal from CompCote International.

Die Castings pose some of the most challenging problems in anodizing.  This paper provides some explanations by tying together metallurgical science with anodizing practice.

Die castings pose some of the most challenging problems in anodizing.  The finish can be too thin, non-uniform and/or have an unfavorable appearance.  These are common problems with a variety of practical solutions; they are easy to recognize, but in many instances, the source for the problem remains unknown.  Critical to solving the problems of anodizing die castings is understanding the die cast substrate and the impact of surface condition, alloy composition, casting quality and microstructure on the anodizing process. Substrate quality issues are just as important, maybe more so, than anodizing conditions and technique.  Certain optimum anodizing conditions may be used in some cases to help overcome less than advantageous metallurgical conditions.  These include well known processing tools such as various pretreatment chemistries, higher anodizing bath concentration, and higher bath temperatures. These, and other recommended solutions are not successful in every case; sometimes trial and error testing on actual production parts must be done to find the best processing techniques.  Through the use of actual case studies that provide real-life solutions in terms of anodizing theory and interfacial science, this paper provides some explanations by tying together metallurgical science with anodizing practice.

To read the complete article from Products Finishing Magazine click here.

This post was provided by:  Products Finishing Magazine

Something for Everyone in Your Office at the Aluminum Anodizing Conference!

While keeping up to date on the technology is essential to any business trying to stay ahead of the curve, there is much more to run a successful business than that one aspect.

AAC will stay on top of its game with15 presentations in three important focus session tracks: 

·         Recycling

·         Color & Texture

·         Technical presentations

In addition, this year, they have added the best management and marketing sessions ever offered.  From Team Building and Employee Engagement … to Managerial Accounting for the Anodizing Shop … and then on to Sales and Marketing of Anodizing Services in the Job Shop, this is a must attend conference!

Guy Charpentier from Bonnell Aluminum will speak on Strategies to Grow Demand for Anodizing Finishing.  If you are in the anodizing industry, you will want to hear this presentation which will provide you with strategies aimed at growing the demand for anodized finishing in the commercial architectural market.

Lynn Brown (Long Point Associates) who is the industry consultant to the Aluminum Extruders Council will speak on Aluminum and the Road to 54.5 Implications for Anodizers.  When Ford launched the 2015 F-150 earlier this year, the general public caught on to the fact that those in the aluminum world have known for several years – that aluminum will play a major role in the automaker’s plans to greatly improve fuel efficiency and reduce their carbon footprint.  This session will look at the accelerating use of aluminum in North American autos, the issues yet to be resolved, and the implications of this market on the development for anodizers.

The 2014 AAC conference is jammed packed not only with amazing technical sessions but also with the best management and marketing sessions ever offered.  AAC is also offering their Level 1 Workshop (Anodizing Essentials) and their Level 2 Workshop (Quality Anodizing). 

In addition, there is a tour to the Alcoa Technical Center offered.

There is something for everyone in your office at the AAC Conference in Pittsburgh, Pennsylvania!  For full conference session offerings click here.

Bring your team … and get the group discount by registering 3 or more people from your company by Sunday, August 17, 2014!  Register today!

 

Fair Trade Initiatives to the Rescue

Five years ago, major players within a key segment of the North American aluminum industry came together to defend their markets from an existential threat.  That threat was seen in the surge of extruded aluminum product, much of it anodized, being imported into the U.S. and Canada from China.

What followed is described by some as a “defensive strategy” to protect previously tariff-free and highly competitive markets from the detrimental effects of unfair trade practices, such as government subsidization and predatory under-cost pricing (dumping).  Aluminum extruders and aluminum product manufacturers in the United States and Canada, along with their trade association groups such as the Aluminum Extruders Council and the Curtain Wall Coalition, petitioned their respective governments for protective tariffs to level the playing field.  Those efforts were successful.  As a result, this key segment of the aluminum industry remains safe and intact.  To read more about this strategy, go to: http://aluminumextruderscouncil.blogspot.com.

Note that this surge in imports from China peaked in 2009, just as the North American economy was feeling the brunt of the post-housing-bubble recession.  AEC’s Jeff Henderson writes in his current blog (linked above) that the effect of fair trade initiatives is to have ”delivered over one billion more pounds in aluminum extrusion shipments in 2013 as compared to 2009. This 32% increase in volume has led to extruders investing over seven hundred million US dollars in the past two years.”  That is really the bottom line.  Fairness led to competitiveness.  And that led to more business, more jobs and, one could argue, better products for customers. 

Have aluminum anodizers and other metal finishers benefitted from this?  There is not a lot of hard evidence on this, but common sense indicates the answer is “yes”.  A myriad of consumer and industrial applications were targeted by the Chinese.  Anodized and fabricated extrusions would have been easy targets.  As more orders began pouring into North America, it became easier for custom service offerings using domestic warehouses to deliver just-in-time delivery programs.  With subsidized production, artificially low prices, special delivery systems, and improving quality, the growth in Chinese extrusions had no barrier.  In short, this portion of the domestic aluminum manufacturing industry was in dire peril of being completely outsourced.

Fortunately, due to the foresight and diligence of leading aluminum manufacturers, that didn’t happen.  My trade association, the Aluminum Anodizers Council has remained aware and supportive of efforts to restore and maintain fair trade.  AAC believes global trade is good for competition and consumers, but only when it is conducted freely and fairly.  The Chinese cut corners in attempting to dominate world supply in basic manufacturing industries such as aluminum parts.  When that happens, tariffs can restore a healthy competitive balance.  That is exactly what happened in the aluminum extrusion markets in North America.  Thank goodness. 

This Blog was submitted by:  Rand A. Baldwin, CAE, is the President of the Aluminum Anodizers Council. 

Mr. Baldwin is the chief of staff for the Aluminum Anodizers Council, a not-for-profit trade organization representing the interests of aluminum anodizing firms, suppliers and other members of the aluminum anodizing industry.  For more information, see www.anodizing.org.
 

Aluminum Anodizing Conference Registration is Now Open!

The AAC Conference is going East, we will be in Pittsburgh, Pennsylvania this September for our Annual Conference.  

Register Now!

Here are some of the conference highlights:

Monday, September 15

·         Anodizing Essential Workshop (Level 1) – Full Day

Tuesday, September 16

·         Anodizing Quality Workshop (Level 2) – Half Day (morning session)

·         Alcoa Technical Center Tour

·         Welcome Reception & Anodizing Expo

Wednesday, September 17

·         General Sessions:

o   Aluminum and the Road to 54.5 Implications for Anodizers, Lynn Brown, Long Point Associates and AEC Industry Promotion Consultant

o    Recent Developments of Colored Anodic Films for Space Applications, Professor Laurent Arurault, CIRIMAT – Université Paul Sabatier

·         Focus Sessions featuring 15 topic-specific presentations in three concurrent tracks (Recycling Track, Technical Track and Color & Texture Track)

·         Reception & Anodizing Expo

Thursday, September 18

·         General Sessions: 

o   Team Building and Employee Engagement, Vance Jones, Easton Technical Products

o   Managerial Accounting for the Anodizing Shop, Kevin Janis, Reliant Aluminum Products, LLC

o   Sales and Marketing of Anodizing Services in the Job Shop, Jack Tetrault, D-CHN

o   Strategies to Grow Demand for Anodizing Finishing, Guy Charpentier, Bonnell Aluminum

Exhibit space and Sponsorship opportunities are still available!

We hope you will join us in Pittsburgh!

 

 

Precise Control of Anodizing Bath Temperature Helps Assure Repeatability of High Quality Anodic Coatings

The ability to maintain consistent bath temperature in the anodizing tank is one of the most important factors in producing consistently high quality anodic finishes.  It is widely accepted that the temperature range for Type II and Type III anodizing is + 2^o F (1^oC).  Other anodizing processes such as phosphoric acid and chromic acid (Type I) anodizing don’t have quite as stringent requirements. 

While anodizers know that an anodizing bath must be cooled, most anodizing tanks require both heating and cooling.  Only the subject of cooling is addressed in this article.

When bath temperatures exceed the range limits the coating characteristics are more difficult to control.  As bath temperature increases it becomes more conductive.  This allows slightly higher current flow, which results in higher current density, and the anodic coating is formed faster.  The opposite is true when the electrolyte is “too cold.”  Wide variation in bath temperature can affect the anodic pore size, coating thickness and coating hardness and can even affect the way a load seals.  The coating characteristics can vary from load to load if the bath temperature is not consistent.  This results in difficulty of color matching, especially on dyed or electrolytically colored parts, but also on clear anodized parts.

There are two common methods of cooling the sulfuric acid anodizing electrolyte:

 

1. Placing a cooling coil directly in the anodizing tank.
2. An external heat exchanger system.

Placing the cooling coils in the anodizing tank can be problematic for several reasons:

• Some coils are delicate and can be damaged by what is going on in the tank.


• Coils are susceptible to holes due to electrolytic and/or chemical corrosion leading to possible contamination of the bath from the coolant.


• Coils made of titanium or zirconium are extremely expensive.


• The relationship between cooling coils and tank cathodes have a history of being complicated and troublesome.

An external heat exchange system is removed from the harsh environment of the anodizing bath.  Electrolysis, bath air agitation and accidental contact between the anodizing loads and cooling coils are not factors with an external temperature control system.  Other advantages of external systems  are:

• Usually less expensive than coils placed in the tank, depending on the size of the tank.


• Easier to maintain because an external system is not in the tank itself.


• A plate heat exchanger is a more efficient heat transfer mechanism than cooling coils.


• Less wear and tear overall.


• Pumped, circulating acid provides another means of bath agitation.


• A filtering system may be easily incorporated.


• Acid circulating pump is an easy way to pump the tank for maintenance.

Whether the anodizer chooses cooling coils or the external heat exchanger method, regular and proper preventive maintenance is a requirement for effective and efficient long term performance of the cooling system.

 This post was written by AAC Member Larry Chesterfield of Anodizing Technologies Incorporated.

AIA Convention Coming to Chicago in June

The American Institute of Architects will hold the annual National Convention and Design Exposition   June 26-28 at McCormick Place in Chicago, IL.  

With nearly 800 exhibitors and more than 200 seminars and workshops and 80 educational tours, this is the largest gathering of architectural professionals in North America.

In a recent membership survey of Aluminum Anodizers Council members, Architecture was rated as the number one end market for anodized products.   Several AAC members will be exhibiting and participating in the AIA Convention.   For more information, go to www.aia.org.

SAVE THE DATE! AAC’s 2014 Anodizing Conference: September 16-18, 2014!

The Annual Anodizing Conference and Exposition is scheduled for Tuesday, September 16 through Thursday, September 18, 2014 at the Pittsburgh Marriott City Center in Pittsburgh, Pennsylvania.  Plan now to participate in this highly educational conference and expo designed by aluminum anodizing professionals for the anodizing community.

Reservations for rooms at the Pittsburgh Marriott City Center are now being accepted. The AAC group rate is $159 (USD) per night/single or double occupancy plus tax.  To receive the special AAC rate, make your room reservation by August 25, 2014.  Please refer to the AAC Conference website (www.aacconf.org) under travel and lodging to book your room.

Information on Conference Registration (fees and online registration) will be available by late- June.  Please check the AAC conference website for more details as they become available.

Exhibit & Sponsorship Opportunities for Annual Anodizing Conference Soon!
Suppliers to the anodizing industry are encouraged to make plans to exhibit at the Anodizing Expo, which will be open during the Welcome Reception on Tuesday evening and all day on Wednesday from breakfast through the Reception in the evening.  The Council currently is preparing the Anodizing Expo Prospectus, which will outline the exhibiting and sponsorship opportunities available.  Complete details will be available in June or visit the conference page of the AAC website at www.aacconf.org for information as it becomes available.