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ALUMINUM FABRICATION

SORTING OUT ALUMINUM SAWING AS ALUMINUM COSTS DROP, THE MATERIAL IS FINDING NEW APPLICATIONS THAT PUSH THE ENVELOPE ON HOW MUCH OF THIS METAL CAN BE USED IN THE STRUCTURAL MAKEUP OF A VEHICLE — WITH NO END IN SIGHT.

By Joseph Suydam

n the fabrication industry, lightweighting has been a primary focus I in the automotive sector to produce a final product that is as fuel effi- cient as possible. With research and development constantly enhanc- ing the mechanical properties of aluminum alloys to produce the best possible strength-to-weight ratio, it’s easy to see why aluminum has become a go-to in vehicle construction. Beyond its lighter weight, which can enhance fuel efficiency and performance capabilities, alu- minum is also easily recyclable and in the automotive industry, it can Metal fabricators are investigating how to best improve safety by absorbing more crash energy than . process aluminum alloys as demand for aluminum With the growing demand for aluminum parts in automotive and parts grows in the transportation industry. aerospace, metal fabricators are investigating how to best process aluminum alloys. After aluminum is forged, is one of the first stages done for fabrication. One important aspect to consider is cut- handling is also very helpful with product out- ting methodology. While aluminum is lightweight and comparatively put, since aluminum is a softer alloy and is easier to cut than exotic alloys, it still presents its share of challenges, more vulnerable to dings and dents. Therefore Joseph Suydam such as gumminess, chip packing and deburring. However, with the the removal and transportation of finished Behringer , right equipment, aluminum can be very efficiently sawn via two meth- product is also important. Inc. ods: circular sawing or band sawing. BAND SAWING CIRCULAR SAWING Recent advancements in band technology and their ability to Generally, one of the most accurate and fastest sawing methods for run at high surface feet per minute (sfm) has allowed band cutting aluminum alloys is with the carbide circular . Since saws to also make quick work of aluminum alloys. Historically, band aluminum is a lighter material it makes sense to cut it with higher speeds saws couldn’t generate enough band speed without complications and feeds and circular saws cut very fast. In addition, a that led to damage and scrapped parts. Years of research blade has to be more than twice the diameter of the part being cut. The and development have resulted in band saws that can now reach larger, heavier blade often requires a larger saw and footprint. Thus to over 4,000 sfm, with the stability and blade tracking necessary to no surprise, the circular saw is a relatively expensive capital investment, cut efficiently through aluminum. This is good news for aluminum and the blades are more expensive than band saw blades. The ability fabricators because not only is the blade itself less expensive than to turn the blade at such a high rpm also requires a robust and stable a carbide circular blade, but the price to capacity range is so much saw, built and designed specifically for such an application. more diverse than that of a circular cold saw. The speed at which the circular cold saw can produce finished The most critical part of cutting aluminum is during the entry and products also lends itself well to the integration of a material han- exit of the material, where the possibility of blade damage is the great- dling solution, to keep pace with the cutting production. Depending est. But today’s band saws now allow the operator to program ramp on many factors, including the size, grade, and length of cut, it may feed and speed, which allows the blade to enter the cut slowly, ramp take only seconds to minutes to completely cut up a 20 ft aluminum up speed, and then slow again as it exits the cut. This type of control billet. The operator then has to remove the finished parts and load greatly reduces or eliminates the possibility of blade damage. Some a new bar, leaving the saw idle in the process. Integrating a flat or band saws also feature a servo-driven precision downfeed control that incline magazine that allows the operator to load multiple bars at a automatically adjusts to blade pressure, creating an optimal balance time, enabling the saw to run non-stop for many hours, dramatically of feed rate and pressure for improved quality and cutting rates. The increases productivity and minimizes non production time. Material downfeed power/saw blade pressure is monitored by a cutting pres-

32 FABRICATING & MARCH 2016 fabricatingandmetalworking.com sure sensing system to assure an optimum balance between blade feed and pressure. Operators can therefore maximize material feed rates without concern of overloading the blade. Also, an electrically powered ball screw-driven material feed gripper eliminates backlash and ensures precise material positioning for improved length accuracy. Further advancements in blade designs have also allowed band saws to become a viable cutting option for aluminum fabrication. Traditionally, bi-metal band saw blades typically used with band saws had a rake set that left “shadow” lines or material build up on the part. However, band saw blades are now available with carbide tipped teeth, special coatings and tooth designs that produce an exceptional This Behringer HBM-800-ALU automatic band saw for cut with a clean, flat, smooth surface. Band saws also offer another aluminum is ideal for economic, precise cutting of 800 mm important advantage: less material loss. Band saw blades produce round and 800 mm x 800 mm material. Its 22 kW drive a kerf that is generally one third to half as thick as a kerf produced and frequency control achieve the higher cutting speeds required to process aluminum with little vibration. A servo drive and ballscrew enable rapid feed by circular saw blades. The thinner kerf produced by a band saw of the saw frame and a constant, precisely adjustable saw feed. Two self- blade minimizes material loss and enables a higher yield of finished realigning brushes clean adhering chips off the saw band during cutting into pieces per unit of stock. the funnel-shaped machine frame, which directs the chips into a conveyor under the machine for effective disposal. CHOOSE CAREFULLY When choosing the best saw for cutting aluminum it’s important to consider your application. If you are running high-volume jobs of over vibration dampening and the necessary speed, controls and material 5,000 parts per shift and cutting aluminum between .5 in and 6 in handling options to process aluminum. While both circular and band diameter, and require the best possible finish, a circular saw may saw methods are effective for cutting aluminum, it pays to weigh all be the best option. For lower-volume fabricators that cut a variety the factors before deciding which saw is best for your operation. of other materials, a band saw for high-speed cutting of aluminum stock over 6 in diameter might be the better solution. But regardless Joseph Suydam is an inside sales engineer at Behringer Saws, Inc., 721 of which method a fabricator uses, it is critical to invest in a saw that Hemlock Road, Morgantown, PA 19543, 610-286-9777, joseph.suydam@ is well made, has a cast iron frame and components for rigidity and usa.behringer.net, www.behringersaws.com.

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