Ken Healy, Executive VP & Director of Engineering and John Perrotto, President
Be it preparing an aircraft for routine surveillance or launching missiles in times of war, precision is of paramount importance in the aerospace industry. Traditionally, the requirement for precision meant high cost with limited options for manufacturability. That praxis, however, is shifting as competition and budgets are pressing the industry for greater value. This necessity has opened the door to exploring alternative methods of manufacturing that can deliver close tolerances and reliability while maintaining weight and safety considerations.
A process that is gaining notoriety, particularly in aerospace, is flowforming. Flowforming in combination with deep drawing and other forming operations offers a high level of design flexibility and provides one of the best and most economical methods of producing high-precision, rotationally symmetrical, hollow parts. Flowforming is a cold-extrusion, metal-forming process that creates seamless and contoured near-net-shaped components from common forms of materials. Material is only displaced, not removed during the process. Thus, unlike the common method of manufacture utilizing forgings, only to machine away up to 85% of the material, flowforming ensures the optimal utilization of raw materials, thereby reducing wastage of expensive metals and alloys.
The team at PMF Industries, led by John Perrotto and Ken Healy, is perfecting the combination of flowforming with deep drawing, machining and other processes, as they have pioneered the technique, and are able to manufacture design challenges not achievable by flowforming alone.
First, the team at PMF receives information from the customer regarding the specified part. This is followed by PMF reverse engineering the customer’s designs to establish a “preform”. The “preform” is the starting component prior to flowforming. This “preform” can be manufactured by deep drawing, forgings or machined bar.
The “preforms” used in the process are engineered for each specific design or shape and is unique to each customers specification. A series of constantly spinning wheels come in contact with the material, giving it a near net shape of the final product.
PMF’s flowforming machines are state-of-the-art Computer Numeric Control (CNC) and can hold precise control of wall thickness and profiles of ±.005” or better with final wall thickness ranging from 0.015” to 0.625”.
Materials that can be flowformed include stainless steel, high strength low alloy steels, Inconel®, Hastelloy®, brass, aluminum and many other metals.
The sophistication of flowforming processes has enabled PMF to produce economical and lightweight parts, including drive shafts, pressure accumulators, hydraulic cylinders, vibration dampening mounts, and accumulator housings for aircraft landing gear among others. Besides maintaining a low ‘buy-to-fly ratio’, the flexibility of the process allows PMF to combine multiple metal-forming techniques in order to increase its versatility for aerospace applications.
“Our company’s uniqueness lies in the aspiration to help the engineers at the clients’ workplace get acquainted with flowforming techniques. Engineers learn the benefits of flowforming in reducing operational costs while understanding the opportunities to make more sophisticated machine parts,” explains Perrotto, President, PMF. Added to that, PMF takes pride in being an AS9100 certified company that ensures high-quality result delivery. The company also boasts the National Aerospace and Defense Contractors Accreditation Program (Nadcap) certification in heat treating, welding, non-destructive examination, and non-conventional machining.
PMF is highly proficient in evaluating the existing design of the machine parts used by the clients and identifying the areas to increase the tolerance levels of the materials, simultaneously attempting to form a radius, based on which the roughness of machine parts at their edges would be reduced. In an instance, PMF had assisted a client in amending a machine part that was initially developed in four different sections and then welded together. In doing so, PMF helped the client avoid high costs of manufacturing.
Scripting such success stories, PMF is currently focused on starting its in-house vacuum brazing while continuing to improve its existing flowforming procedures. “With our consistent teamwork, we aim to enhance our offerings for clients, thereby addressing their challenges for efficiently,” concludes Perrotto.