Page 35 - MetalForming March 2019

FABRICATION
Waterjet
Shines for Metals and More
Gentle supersonic erosion and a very thin cutting stream provide manufacturers with a versatile and capable tool.
While often employed for com- mon materials such as steel, aluminum, gasket and foam, waterjet cutting capabilities shine brightest in the opinion of many when it comes to tougher applications such as exotic metals and alloys (titanium and Inconel), stone, composites, thick insulation and cement board.
The first three—exotic metals, stone and composites—use abrasive waterjet streams and the last two, pure waterjet.
Cutting Exotic Metals and Alloys
Abrasive waterjet cuts many mild steel and aluminum grades, as well as exotic metals used in advanced appli- cations, which pose problems for other cutting processes. Harder and lighter than steel, and used in applications such as aircraft and others where weight should be reduced, titanium alloys prove difficult because cutting via a mill is very slow, generates a lot of heat and quickly wears out the bit. The same holds true for nickel alloys, which remain stable at high temperatures and often find use in engines where components should not enlarge or deform with extreme heat.
When used for these materials, abra- sive waterjet produces either highly accurate finished parts, or will rough cut a part to a good tolerance to later be finished on the mill. Combining waterjet cutting with mill finishing reduces processing time and saves expensive material due to the thin kerf cut of abrasive waterjet. A waterjet machine can cut titanium faster than steel, and nickel alloy at approximately
In addition to mild steel and aluminum, an abrasive waterjet stream cuts exotic metals such as titanium and nickel alloys.
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the same speed as steel.
Metal fabricators not only efficiently
cut alloys, but find that their machines provide opportunities in other material applications. Here are a few of those applications.
Stone
Kitchen and bathroom countertops made of granite, marble or engineered stone; stone inlays, artistic pieces used to beautify hotel-lobby floors; and table tops, often are cut via abrasive waterjet.
Alternative methods for cutting stone in these applications include saws, routers and grinding. However, the abrasive waterjet’s thin stream and the fast and simple art-to-part sequence frees designers from manufacturing limitations, making detailed cutting patterns possible.
Composites
Composites, highly engineered materials usually selected for use because of their strength-to-weight ratio, are stronger per pound than metal but lighter, thus delivering a weight reduction that’s highly desir- able in transportation and sporting applications.
Composites such as fiberglass and carbon-fiber-reinforced plastic present process challenges for sawing, milling, routing or burning, and usually are comprised of two components: some type of resin epoxy and cloth made of fibers. The epoxy can burn and the fibers can become damaged during cutting. Engineers using composites avoid epoxy burning, micro cracks, and delamination, as well as fiber pull out, breakage and whiskers by using