Laser heat treating makes use of the laser energy to rapidly and efficiently heat a selected area of the surface of a metal component above the transformational temperature. The thermal mass of the component is all that is required to achieve quenching. In other words, a rapid quench necessary for hardening is achieved by removal of the laser energy via conduction. This occurs after turning off the laser or movement of the laser beam over the component’s surface. Rapid heat removal is achieved by the thermal mass of the component acting as a heat-sink. This heat removal rate is typically much higher than those associated with traditional methods and therefore can achieve a higher case hardness.

The major advantage of diode laser surface hardening is the high processing speed with precise case-depths resulting in negligible distortion. Laser surface transformation hardening not only increases the wear resistance; but, under certain conditions, the fatigue strength is also increased due to the compressive stresses induced on the work piece surface. This is especially true of powder metal parts and high torque parts such as cams, cranks, and couplings.

All heat treatable materials can be laser case hardened without liquid based quenchants. The low distortion is what makes the process a clear winner over traditional heat treating methods such as flame, RF-induction, furnace, carbonizing, and nitriding processes. Flame hardening has poor reproducibility, poor quench, and large distortions. Induction hardening requires precise controls over inductor placement, quenchant chemistries and flow, but still produces large distortions due to large thermal penetration. Furnace, carbonizing and nitriding processes are all inherently non-localized and therefore are distortion risks.

The diode laser is an ideal source for laser transformation hardening, with the most absorbing wavelength of any laser, the diode requires no pre-coating of a machined work piece surface to achieve light absorption. The diode laser is inherently solid-state, which allows for in-situ temperature control, thus we can provide a level of quality not achievable with any other heat-treating process.

Titanova diode laser heat treating service is a much more cost effective heat treating technique when compared to traditional heat treating processes when one considers first time quality, turn around time, pre and post part processing requirements. The diode laser heat-treating process is inherently a LEAN [single piece flow] process. Since diode laser heat treating is a localized heat treat, only where the laser beam points, distortion can be significantly reduced or eliminated.  For ferritic cast irons we have a proven Laser Glazing process.