By Dan Davis
Combining advanced laser control, new assist gas hardware, and non- contact part mapping now allows fabricators to significantly reduce the cycle time in cutting 3-D parts produced from high-strength, low-alloy
(HSLA) plate, according to the laser experts at Prima Power Laserdyne.
By shortening the time for piercing of 5- to 10-mm-thick steel plate in parts
containing several hundred holes, slots, and other shapes, the manufacturer
has reduced the cycle time more than 30 percent compared to traditional laser
processes, said Prima Power Laserdyne President Terry L. Vander Wert.
Fiber lasers with average power of 2,000 W have been commercially available
for more than 10 years. In fact, automotive component manufacturers have embraced this technology in a large way. The fiber lasers in this power range, a majority of which have continuous wave (CW) output, are well-suited for automotive metal cutting and welding applications. That may be changing, however.
Greater Laser Power
Quasi-continuous wave (QCW) lasers produce peak power 10 times greater in
pulsed mode than CW mode, providing new process opportunities in automotive and many other industries, according to Dr. Mohammed Naeem, Prima
Power Laserdyne’s senior manager, applications engineering and technology
development. (CW lasers are the result of power sources that continuously emit
light. QCW lasers have power sources that emit the laser both continuously and
at defined intervals.)
“Major QCW laser enhancements in process speed and quality have been
made recently in both aerospace and medical device manufacturing. These are
now being adopted in other industries, particularly in the automotive sector,”
For Prima Power Laserdyne, innovation in this area has centered around
Smart Techniques™, a suite of hardware, so;ware, and control technology that
is designed to improve productivity and quality in laser processing and provide unique capabilities for high-power laser cutting, welding, and drilling using both CW and QCW fiber laser systems (see Figure 1). In particular, Smart-Pierce™ and SmartSense™, along with a patent-pending gas assist nozzle—all
developed for aerospace applications—hold great promise for the automotive
industry, Vander Wert said.
The Automotive Fabricating Challenge
Automotive applications typically di;er from aerospace applications in a few
important ways. Most automotive parts are fabricated from cold- or hot-rolled
steel, instead of stainless steel and specialty alloys, and production processes
are not as lengthy when compared to aerospace applications, such as an aerospace combustor that requires laser-drilling thousands of holes.
In fact, because of the quantities of the components required, cutting speed
and throughput are the most critical elements of an automotive production process. While automotive parts also require quality and precision, they are more
o;en secondary to processing speed. Edge quality and feature size do not have
the same impact on the performance of an automotive component as they do
on an aerospace component. Cycle time o;en determines process viability for
For laser processing to be deemed acceptable in automotive applications, it
has to perform quickly and produce quality parts. That’s why as Prima Power
Laserdyne worked to commercialize this technology for the automotive industry it set aggressive goals for 5- to 10-mm-thick sections of low-carbon steel.
The cut quality required rapid pierce without spatter. Cuts had to be dross-free
with minimum taper. Features such as slots and holes had to be located within
the required precision, despite the fact that the formed blanks could vary significantly from the design shape. Part-to-part cycle time was the key goal, while
minimizing the cost of optics, assist gases, and other utilities.
Piercing and Processing
Laser cutting thick-section carbon steel traditionally is a gas-assisted process
using either oxygen or an inert gas such as nitrogen. Variables related to the assist gas, such as pressure, nozzle design, and stando; distance, have a big influence on the cut quality. All play important roles in governing the gas dynamics
and significantly influence the cut quality and cycle time.
One of the benefits of using an oxygen assist gas instead of air for automotive
applications is its ability to clear the cut of molten material and produce a dross-free cut. The pressure of the gas is important. With too little pressure the molten
material may adhere to the parent material, forming dross and sometimes sealing and ruining the cut. Too much oxygen can burn and significantly degrade
the cut quality. To avoid failures in these applications, manufacturers prefer
to use oxygen assist gas to achieve a clean cut. Most important, oxygen assist
gas results in faster cutting speeds. Also, the consumption of oxygen is much
New laser cutting technology means newfound productivity
Automakers working with high-strength steel could benefit
This QCW fiber laser is cutting a 10-mm-thick carbon steel automotive component
using the latest Prima Power Laserdyne process for piercing and cutting.
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