Werkstofftechnische Aspekte des Laserschneidens

Abstract

is to reduce the reaction time by reducing the pulse time or increasing the velocity in the case of linear or areal hardening.In our work this caused a reduction in temperature. In Fig. 10 the change in hardness is shown as a function of pulse time and penetration depth. It can be seen that at long pulse times a very thin hard layer is produced. At shorter times this hard surface layer is absent but the general hardness remains the same. 6 ferrite is retained (dotted curve) for low pulse times where the temperature and concentration below the surface are such that 6 is produced on heating (Fig. 11). An optimisation of the process for a rachet tooth flank is demonstrated by the hardness profile in Fig. 12 and the corresponding micrograph. ConclusionsIt has been demonstrated that laser heat treatment and simultaneous gas alloying is a viable proposition. The harden-ing cycle can be controlled to attain the requisite cooling rates for hardening and still be maintained at sufficient temperatures for sufficient periods to absorb the gas. The process was automated to carry out several operations on one workpiece and hence could be used in production processes.

Gaseous alloying with Laser Heating

“…It is also very fine grained. Surface hardening produced by heat treating supersaturated y structures are discussed by Barton [ 2 ] . The two regions are separated by a diffusion zone.…”