Metal Finishing Guide Book

2013

Issue link: https://metalfinishing.epubxp.com/i/218436

Contents of this Issue

Navigation

Page 230 of 843

Numerous anodizers and production facilities have made this electrolyte possible through their sincere professional technical support over more than 50 years of research in problem-solving situations. The following formulation represents only one condensed version of one universal mixed electrolyte for Type IC, II, IIB and III anodize. This electrolyte was also used for selective brush for all three types of anodize (Type 123). This universal formulation was developed after reviewing several different process tanks in production. The ranges marked in red represent a formulation used for Type IC and heavy thickness hard anodize (10 Mils). The low sulfuric acid concentration and high tartaric acid concentration made this possible. The higher concentration Type II – 23 – III HA formulation was used for high production Type II and III anodize in the same anodize tank. The ACEA is an Amino Polycarboxylic Electrolyte Additive/Modifier based on a concentrated MAE Type additive along with amino acids. PROCESS PROCEDURAL REQUIREMENTS: KEY SECRETS FOR SUCCESSFUL ANODIZING After working on numerous problem-solving situations and troubleshooting for various anodize facilities, various procedural requirements were developed4. These procedural requirements should be used for preparing Pulse – Step – Ramp and Run procedures for all types of anodize. Here is how they were presented at anodize workshops: Actual process procedures and/or procedural parameters are the real heart of quality anodize. The key secrets included in this workshop date back 50 years, in some cases. They still remain the basis for most of the finest hard anodize procedures available. ATS was probably the first group to bring them all together for anodize seminars, training programs and workshops. The process procedures presented in this workshop depend upon the strategic use of critical factors, requirements and technology which, when used together as a Complete Spectrum Package (in conjunction with a good electrolyte) during the ramp and run cycles will produce consistently excellent results. Critical requirements developed in part from problem-solving situations are listed below in the order of precedence and can be seen in real-time graphs at the end of this discussion. 1. Activation – Voltage Pulse Early During Ramp (Detailed 3 Stage Pulse – 2012 Paper) 2. Pulse-Step-Ramp (PSR) 3. Increased Dwell Times (3-7) (For Proper Pore Structure Conditioning) 4. Amperage Decay or Drop Off (ADO) 5. Constant Current Density Ranging (CCDR) 6. Process Time vs. Ampere Hours 7. Real-Time Graphic Observation (monitoring for reproducibility) 8. Current/Voltage Spikes or Deviations/CSD Discovery Leading to APCD Activation – Voltage Pulse Early During Ramp: Activating and maintaining activation is very important at the start of (and early in) the ramp cycle. This is accomplished by increasing the current density (5 - 10 ASF for Hard Anodize) within 10–30 seconds after positive bus bar contact in the anodize tank. The current should be slow pulsed 25–50% using anodic discharged surface activation (APCD – if available). Field-assisted dissolution is 225

Articles in this issue

view archives of Metal Finishing Guide Book - 2013