The use of Inconel has become widespread since its development in the 1940s. The exotic metal, a nickel-chrome-based superalloy, is often referred to as “space-grade” due to its use by manufacturers in the aeronautics industry and based on its resistance to corrosion and oxidation and the ability to withstand extremely high temperatures. Despite being far more expensive, Inconel sometimes takes the place of steel. For example, where Tesla would normally use steel on its main pack contractor (a part related to car’s battery pack), in the Model S P90D, Tesla is using an Inconel alloy to achieve more power.
The same properties that make Inconel such an attractive option are the same ones that make it a difficult material for manufacturers to work with. And because of the expense of Inconel alloys, having a remnant pile of it in a shop’s scrap bin can represent a significant waste of money. This is part of the reason for the development of new sawing technology that eases the process.
To address these concerns, HE&M Saw developed a prototype bandsaw. The DC22 is a dual-column, 22-in. capacity bandsaw that includes engineering concepts that allow it to cut smaller pieces of Inconel more efficiently.
HE&M had big plans to showcase the DC22 at IMTS, which was to take place in September. Based on health
and safety concerns, however, the pandemic forced IMTS organizers to cancel this year’s event.
“From an engineering perspective and just showing off what’s new, IMTS is one of the industry’s biggest shows,” says Max Harris, chief engineer at HE&M Saw. Regardless, Harris says that the company is still moving forward with the bandsaw, which will be on the market in mid to late September.
HE&M Saw is no stranger to producing saws geared for cutting exotic materials/superalloys, but it’s been years since HE&M made improvements to pre-existing equipment or offered a new line dedicated to these materials. In developing the DC22, Harris says the goal was to provide manufacturers a more efficient and aggressive way to cut Inconels, and also to improve saw blade life, offer more Industry 4.0 connectivity and introduce high-precision technologies to enhance cut performance.
One of the first steps was to develop a method for cutting “bar end,” otherwise known as remnant material, more effectively. The HE&M team approached the challenge using a split vice configuration, which holds the material on the back side of the blade as well as on the front side of the blade.
“This allows us to hold onto a piece very securely, before and after the cut,” Harris says. “This means you can process the material faster. Also, when the blade cuts through, we can make sure the pieces don’t pinch down. For the smaller remnant pieces, it allows for more security.”
Also new in the DC22 is the Active Cut Watcher, which is an improvement on a patent HE&M has had since Harris’s grandfather and founder of the company, Gerald Harris, developed it decades ago. It originated simply as the “cut watcher” and involved technology that uses a sensor to detect deviations in the blade as it works through the material. When the deviation hits a specific level, the machine shuts down so the material isn’t ruined before the operator can make a correction.
The improvement on that technology involves an additional sensor that further tracks blade deviations and takes corrective action by activating a booster cylinder that puts more tension on the blade to pull it straight. This action not only saves on scrap, it also helps to maintain blade life.
“We’ve added some logic on the back end,” Harris explains of the improvement. “We can counteract that blade deviation while it’s actively in the material. So, as you’re cutting through the
material, you can keep a much flatter cut while being more aggressive with the material and not having to worry about the blade walking all over the place.”
HE&M is working with M.K. Morse on a saw blade specifically for the DC22 to enhance the user experience. M.K. Morse is researching bi-metal and carbide blades for the saw, with a larger focus on carbide as it performs more effectively on Inconels.
“We’re taking their design specs and information and improving our cutting controls,” Harris says of the partnership with M.K. Morse. “We’ve installed a servo control for the saw head as well as a servo on the bar feed. The servo head control allows us to get very accurate pressure and great feedback, so we will be able to build a material library that is optimized for specific materials.”
Information gleaned from the servo controls will also allow users to generate vital information about the saw and the blade, leading to higher quality cuts and prolonged blade life.
Furthermore, HE&M engineers have produced a bar feed system that is capable of moving materials up to 20,000 lbs., where previously it was 10,000 lbs. of material. This gives manufacturers more leeway in working with different/heavier materials.
Yet another development borrowing from an old patent includes HE&M’s Blade Enhancer. The technology allows the blade to intuitively “rock” it’s way through the material. This is important because Inconels can become workhardened, meaning as a blade makes its way through the material and friction (heat) builds up, the material becomes harder, making it take longer to cut and risk fracturing the carbide on the blade. The Blade Enhancer technology utilizes cylinders in the saw’s guide cap to make slight rotations that affect the position of the blade.
“The Blade Enhancer technology changes our attack angle on the material as it starts to become workhardened,” Harris says. “We can actually approach it at a different angle, which should reduce the carbide blade fracturing problem.”
Harris notes that while the blades from M.K. Morse are still in the design phase, any blade made for cutting Inconels will work with the DC22.
Another advantage of the DC22 is its Industry 4.0 integration. HE&M joined MTConnect as a standards committee member to help streamline the process of gaining offline programming
functionality and remote machine monitoring capabilities. MTConnect was established by the Association for Manufacturing Technology, which according to the MTConnect website is the “open-source communication standard for interoperability that offers a semantic vocabulary for manufacturing equipment and devices.”
“It allows our equipment to talk with ERP systems and process monitoring programs and monitor how the process is going,” Harris says.
This interconnectedness plays nice with HE&M’s new approach to its servo control head and bar feed system. Harris says the combination of the two (the servo bar feed has been on HE&M machines for a couple of years) working with smaller material, 48 in. long or less, allows the bar feed to move “much, much faster than in our old systems.” The performance, cycle-wise, is also much improved, particularly in accuracy and repetitive positioning.
“The DC22 machine is becoming more on par with the CNC world,” Harris says, “where we’re getting high-precision manufacturing into the bandsaw side of things.”
Exotic metals, Inconels, bandsaw, Industry 4.0, servos, cutting superalloys