Cathodic Arc PVD Coating Chamber Automation

I designed and implemented a fully automated vacuum chamber specialized for Cathodic Arc Deposition of Nickel-Alloy corrosion-resistant coatings, developed for Chromalloy's aerospace applications. The system executes complex “recipe-based” coating processes—loaded directly from Excel spreadsheets—while automatically setting device setpoints, logging real-time and historical data, and managing alarms. By eliminating manual oversight, the chamber saves ~10 hours of operator labor every other day, greatly improving efficiency and consistency for Acree Technologies.

The system leveraged refactored Allen-Bradley MicroLogix 1400 PLCs integrated with Ignition Edge Control SCADA running on a Windows 11 industrial PC with touchscreen interface. It coordinated a network of 6 RS-232 connections, 15 analog inputs, 7 analog outputs, and extensive digital I/O for precise control of 8 power supplies, a mass flow controller, 2 Heaters, a Motorized Gate Valve, several pneumatic based actuators, a Cryogenic pump, 3 pressure sensors, and a thermocouple.

A major technical challenge was regulating asynchronous communication across multiple RS-232 devices, each with unique protocols (ASCII vs. raw-byte handshake). I developed a robust scheduling and retry logic to maintain deterministic behavior and ensure uninterrupted process stability.

One critical feature of this system is the automatic retriggering of the cathodic arc process after an “arc-out” event. When an arc-out is detected (indicated by the process current dropping near zero), the system actuates a rotary actuator coupled to a stainless-steel rod, momentarily grounding the target. This action reliably re-ignites the cathodic arc, allowing the recipe to continue without operator intervention and minimizing process disruptions.

• Automated 8 Power Supplies, 4 Mass Flow Controllers, Heater, 4 Pneumatic Linear Actuators, 3 Pressure Sensors, Thermocouple, and Motorized Gate Valve
• Cut operator time by ~5-6 hours/day; added robust logging & alarm handling.
• PLC: Automation Direct P-2000 • SCADA: Automation Direct C-More