Apparatus and method for monitoring laser material processing

Apparatus for laser material processing of a workpiece, comprising:

• (a) laser means for generating a laser beam;
• (b) workpiece support means for supporting a workpiece in the path of said laser beam so that a laser generated melt pool is established in the workpiece;
• (c) signal generating means for generating a signal representative of processing quality by monitoring the electric charge distribution in the region of said laser-generated workpiece melt pool;
• (d) said signal generating means comprising a probe device and means for supporting the probe device at a position between said laser means and said workpiece support means, such that the probe device is held at a distance from the workpiece;
• (e) said probe device comprising at least one metal electrode disposed so as to lie near to, but not in contact with, the workpiece melt pool generated, in use, by said laser beam;
• and
• (f) said laser means including a gas nozzle disposed at an output end of said laser means, coaxially with the laser beam, for directing gas towards the workpiece, and said at least one metal electrode of said probe device being carried by said gas nozzle.

Apparatus for laser material processing of a workpiece, comprising:

• (a) laser means for generating a laser beam;
• (b) workpiece support means for supporting a workpiece in the path of said laser beam so that a laser generated melt pool is established in the workpiece;
• (c) signal generating means for generating a signal representative of processing quality by monitoring the electric charge distribution in the region of said laser-generated workpiece melt pool;
• (d) said signal generating means comprising a probe device and means for supporting the probe device at a position between said laser means and said workpiece support means, such that the probe device is held at a distance from the workpiece;
• (e) said probe device comprising at least one metal electrode disposed so as to lie near to, but not in contact with the workpiece melt pool generated, in use, by said laser beam;
• (f) said laser means including a gas nozzle disposed at an output end of said laser means, coaxially with the laser beam, for directing gas towards the workpiece, and said at least one metal electrode of said probe device being formed by said gas nozzle;
• and
• (g) wherein the first mentioned nozzle forming said metal electrode of the probe device is itself embraced and partially enclosed in a non-contacting manner by an electrically conductive second nozzle, to which an electrical potential is applied from a voltage source.

Apparatus for laser material processing of a workpiece, comprising:

• (a) laser means for generating a laser beam;
• (b) workpiece support means for supporting a workpiece in the path of said laser beam so that a laser generating melt pool is established in the workpiece;
• (c) signal generating means for generating a signal representative of processing quality by monitoring the electric charge distribution in the region of said laser-generated workpiece melt pool;
• (d) said signal generating means comprising a probe device and means for supporting the probe device at a position between said laser means and said workpiece support means, such that the probe device is held at a distance from the workpiece;
• (e) said probe device comprising at least one metal electrode disposed so as to lie near to, but not in contact with, the workpiece melt pool generated, in use, by said laser beam;
• an d
• (f) said laser means including a gas-nozzle disposed at an output end of said laser means, coaxially with the laser beam, for directing gas towards the workpiece, said probe means being formed by a nozzle device located at the output end of the laser means for directing a gas towards said workpiece support, including means for electrically isolating said nozzle device from said workpiece support.

Apparatus for laser material processing of a workpiece, comprising:

• (a) laser means for generating a laser beam;
• (b) workpiece support means for supporting a workpiece in the path of said laser beam so that a laser generated melt pool is established in the workpiece;
• (c) signal generating means for generating a signal representative of processing quality by monitoring the electric charge distribution in the region of said laser-generated workpiece melt pool;
• (d) said signal generating means comprising a probe device and means for supporting the probe device at a position between said laser means and said workpiece support means, such that the probe device is held at a distance from the workpiece;
• (e) said probe device comprising at least one metal electrode disposed so as to lie near to, but not in contact with, the workpiece melt pool generated, in use, by said laser beam;
• and
• (f) said laser means including a gas-nozzle disposed at an output end of said laser means, coaxially with the laser beam, for directing gas towards the workpiece, and said probe means comprising a plurality of metallic components which are disposed equidistantly around the laser beam axis and at a uniform distance from said workpiece support, there being provided a means for monitoring the potential difference between said plurality of metallic components.