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CTMA Project Completion: Implementation of Innovative Hard Chromium Plating Tooling at Corpus Christi Army Depot (CCAD) – Phase II

The no-mask concept is relatively new to chromium plating. It involves the design/fabrication of a rack and anode fixture, which are customized to particular parts. The main advantages of this approach are reduced labor for masking, faster plating times and more uniform chromium deposits.  Hard chromium plating provides superior wear resistance for a wide variety of surface geometries. Considerable effort has been made over the past 20 years to develop alternative processes that can match the characteristics and performance of hard chromium plating. However, no single alternative has been accepted as a replacement and the hard chromium process is not likely to be superseded in the foreseeable future for critical applications. The results of this project will enable plating facilities to produce higher quality parts with substantially less time and effort than was possible with previous technology.

During Phase I, the concept of no-mask tooling was introduced to CCAD through the design, fabrication and implementation of custom tooling for two frequently plated aircraft parts. This tooling was well received by the plating shop and was fully integrated into their production activities.

During Phase II, custom no-mask anodes were designed, fabricated and implemented for an additional six frequently plated aircraft parts (two during Phase I and six during Phase II), plus design changes were made to one of the Phase I anodes. Also during Phase II, generic tooling was developed for several less frequently plated parts.

Combined, the new tooling is now used for plating greater than 80% of the total hard chrome plating production load at CCAD. An overall summary of the CCAD tooling resulting from their participation in the CTMA program includes:

Key benefits derived from Phase II of the project include:

• Cycle Time:  The parts selected for Phase II represent approximately 2,800 parts/year. The processing time for these parts was reduced by an average of 32.4% (range of 27.0% to 49.1%). Cycle time benefits were derived mainly from reduced masking and plating times.

• Cost Avoidance:  An annual cost avoidance of $1,067,134 will be achieved from implementation of the new tooling as a result of plating shop man-hour reductions.  Cost avoidance is due mainly to elimination of masking.

• Reliability:  The increased quality of the chrome coating is expected to improve reliability, although it takes years of field service before this expectation can be confirmed.

• Availability:  The new tooling increases existing chrome plating tank capacity by 50.2% (achieved as a result of average reduced plating tank residence time for the selected parts). This benefit is particularly important since tank capacity was previously insufficient; occasionally causing impacts to the overall CCAD production rate.

The NCMS contact is Paul Chalmer, paulc@ncms.org, 734-995-4911.