SYNRAD, INC. - http://www.synrad.com  
Thursday, January 30, 2003
Issue 55

SYNRAD's sealed CO₂ lasers are used in a variety of industrial processes including cutting, welding, drilling, and marking. This news brief showcases some of the interesting materials and products that are processed daily by Synrad's line of CO₂ lasers and marking heads.

Cutting Chrome- moly Steel

Cross-sectional view of 0.095"-thick 4130 chromium-molybdenum alloy steel that was cut using a 240W Evolution laser and 50psi oxygen assist gas.

   4130 chromium-molybdenum steel is a popular alloy in the aircraft industry because of its strength, weldability, and response to heat treatment.

The chromium-molybdenum steel sample shown on the left was cut using 240W of power at a speed of 63 inches per minute (IPM) using 50 PSI oxygen as the assist gas. Focusing was through a 2.5" positive meniscus lens having a 0.07" depth of focus, which produced a 0.004" diameter beam spot. 

   Chromium has an affinity for oxygen, and in high chromium content (stainless) steels, the chromium combines with oxygen to form a Cr2O3 barrier that seals the metal surface, which serves to inhibit corrosion. When laser cutting high chromium steels using oxygen assist however, chromium generally is synonymous with burring because of the chromium/oxygen reaction. For example, 304 stainless steel typically contains 18% chromium and cut edges exhibit a heavily oxidized face. In spite of the name, 4130 chromium-molybdenum typically contains only 0.50% –0.95% chromium content and cuts well, similar to mild steel.

   For more information on metal cutting, the Synrad Applications Lab recommends reading CO2 Laser Cutting by John Powell, which also serves as an excellent reference for CO2 laser processing in general.

Cutting Synthetic Rope

Sections of synthetic rope cut using a Firestar 
f100 laser.

   During their production process, lengths of synthetic rope are typically cut using a hot wire or mechanical cutters, and the resulting frayed ends are sealed in a secondary process. By installing a sealed CO2 laser on the production line, cutting and sealing is reduced to a one-step process because the laser provides clean, sealed cuts. In addition, laser cutting is a non-contact process which eliminates downtime associated with blade or wire replacement. 

   The synthetic rope sections shown in this photo were all cut with 100W of power and 10 PSI air assist using a 7.5" focal length lens to provide a 0.012" diameter spot with 0.52" depth of focus.

   Cut speeds vary depending upon rope diameter and weave of the material.  The 0.75" diameter red rope was cut at a speed of 9 inches per minute (IPM) while the 0.75" blue rope was cut at a speed of 12 IPM. Both of the 0.5" diameter blue and white ropes were cut at a speed of 25 IPM.

Marking Ferrite

   Ferrite beads are often used in electronics to suppress electromagnetic noise, especially in radio frequency (RF) circuits. 

   This ferrite bead was marked using a Synrad 25W laser, an FH Series marking head, and WinMark Pro laser marking software. The FH head, which provides the ability to steer the laser beam, used an 80 mm lens to produce a 116 micron (0.005") spot size at the point of focus. Velocity was set at 20 inches per second, resulting in a cycle time of 0.08 seconds to mark the six 0.045" tall characters.

Browse Synrad's Applications Database

Search our online library for more applications of Synrad's sealed CO₂ laser technology. Sort by material, process, or industry.

http://www.synrad.com/search_apps/Default.htm

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