Following previous experiences at Corpus Christi Army Depot (CCAD), Ogden Air Logistics Center (OO-ALC), and Warner Robins Air Logistics Center (WR-ALC), where implementation of innovative chrome plating tooling avoided about $1 million in annual costs at each facility, the National Center for Manufacturing Sciences (NCMS) Commercial Technologies Maintenance Activities (CTMA) program approved funding for the Implementation of New Commercial Hard Chrome Plating Tooling at Naval Air Systems Command Depot North Island project.

The objective of this project was to introduce new electrodeposited hard chrome plating equipment into Naval Air Systems Command (NAVAIR) Depot North Island maintenance activities, including advanced racks, fixtures, and anodes.

During this CTMA Hard Chrome North Island project, “no-mask” anodes for hard chromium plating two aircraft parts (F-18 landing gear axle and crank) were developed and implemented. Selection of these particular parts was based on:

• High production frequency

• Labor intensive to mask

• Long plating cycles

• Labor intensive to machine (finish grind)

• High reject/rework rates.

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:

• Eliminates labor-intensive masking step

• Faster plating rates

• Reduces plating thickness requirements due to uniform deposit

• Reduces subsequent machining time

• Allows more parts to be plated simultaneously (i.e. uses less tank space)

• Uses less energy.

A baseline was established by monitoring key production parameters (e.g. plating rates, uniformity of deposit, associated production costs). New prototype tooling was designed, fabricated and tested and changes in production parameters, including costs and process steps were measured and documented.

Overall, the project involved several stages of prototype design, fabrication and testing. A final set of production tooling was then supplied and NAVAIR Depot North Island employee training was performed. By the end of the project, the new tooling developed during the course of the work had been incorporated into the facility’s hard chromium plating operations.

Hard chromium plating provides superior wear resistance for a wide variety of surface geome­tries. Although there has been considerable effort over the past several years to develop alternative processes that can match its performance and flexibility, hard chromium plating is not likely to be superseded in the foreseeable future for many 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.

Key benefits derived from the project include:

• Increase in plating rates for the selected parts from 0.4 mils/hour to 1.0 to 2.0 mils/hour

• Improved readiness attained by reducing shop turnaround time by 65% and 74% respectively for the axle and crank

• Labor cost avoidance of $2,472 and $942 per part, respectively for the axle and crank

• Projected annual labor cost avoidance of $145,848 and $47,100, respectively for the axle and crank tooling

• Projected payback periods of 47 days and 77 days, respectively for the axle and crank tooling.

Based on the success of prototype tooling tests, the Navy is considering use of no-mask tooling for chromium plating other aircraft parts. The initial list includes eight parts. Based on the current production rates for these eight parts and using the annual cost avoidance for the F-18 axle as a guide, the projected collective annual cost avoidance from use of no-mask conforming anodes for these additional eight parts is $1,200,000. Implementation costs, including no-mask anodes, would be approximately $200,000.

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