This specification describes systems, methods, and architectures related to generating a plasma shield for laser operations. An example system for generating a plasma shield includes a laser head for directing a laser beam towards a target area on a workpiece. The path of the laser beam from the laser head to the target area on the workpiece is substantially surrounded by a plasma shield, which may form a gas-impermeable barrier. The plasma shield is configured to prevent the ingress of atmospheric or environmental gases, for example oxygen, into an area which would allow the gas to be in contact with the area of the workpiece being interacted with by a laser beam. The shape or location of the plasma shield may be controlled or altered using a magnetic field.

Methods for direct writing of single crystal super alloys and metals are provided. The method can include: heating a substrate positioned on a base plate to a predetermined temperature using a first heater; using a laser to form a melt pool on a surface of the substrate; introducing a superalloy powder to the melt pool; measuring the temperature of the melt pool; receiving the temperature measured at a controller; and using an auxiliary heat source in communication with the controller to adjust the temperature of the melt pool. The predetermined temperature is below the substrate's melting point. The laser and the base plate are movable relative to each other, with the laser being used for direct metal deposition. An apparatus is also generally provided for direct writing of single crystal super alloys and metals.

An adjustment collar for a laser machine tool includes a first actuator between an outer housing and an inner collar, the first actuator operable to move the inner collar with respect to the outer housing in the X-axis and a second actuator between the outer housing and the inner collar, the second actuator operable to move the inner collar with respect to the outer housing in the Y-axis.

Air management systems are provided for optimizing airflow in laser welding with deflectors. A system for a welder includes a blower to generate an airflow stream. A plenum receives the airflow stream, directs it toward the workpiece, and defines an outlet facing the workpiece to expel the airflow stream toward the workpiece. A deflector adjacent the outlet is formed as a conical section converging from the plenum toward the workpiece, and is defined by an angled wall with an open center. The deflector concentrates the airflow stream to impart a velocity increase to the airflow stream after leaving the outlet and to impart a favorable directional component to the airflow stream toward a weld zone, as well as protecting the laser lens by increasing the downward momentum force of the air stream to eliminate the potential of spatter impinging the lens.

An article includes a ceramic material and features a machined surface that is characteristic of cold ablation laser machining, and the machined surface exhibits no visible oxidation. A laser machining apparatus and technique is based on cold-ablation, but is modified or augmented with an inert assist gas, to minimize deleterious surface modifications and mitigate the oxide formation associated with laser machining.

An article includes a ceramic material and features a machined surface that is characteristic of cold ablation laser machining, and the machined surface exhibits no visible oxidation. A laser machining apparatus and technique is based on cold-ablation, but is modified or augmented with an inert assist gas, to minimize deleterious surface modifications and mitigate the oxide formation associated with laser machining.

A method for laser cutting a workpiece having a thickness of less than 6 mm includes the steps of directing a first laser beam, a second laser beam, and a gas jet at an entrance surface of the workpiece such that the first and second laser beams at least partially overlap one another on the workpiece. The first laser beam has a smaller focus diameter than the second laser beam, a beam parameter product of the first laser beam is at most 5 mm*mrad, and a power proportion of the second laser beam of a total laser power is less than 20%. A cutting kerf with a broken cutting edge is formed on the entrance surface of the workpiece.

A method for laser cutting a workpiece having a thickness of less than 6 mm includes the steps of directing a first laser beam, a second laser beam, and a gas jet at an entrance surface of the workpiece such that the first and second laser beams at least partially overlap one another on the workpiece. The first laser beam has a smaller focus diameter than the second laser beam, a beam parameter product of the first laser beam is at most 5 mm*mrad, and a power proportion of the second laser beam of a total laser power is less than 20%. A cutting kerf with a broken cutting edge is formed on the entrance surface of the workpiece.

A laser processing system includes: a wavelength-variable laser device configured to output each of a laser beam at an absorption line as a wavelength at which light is absorbed by oxygen and a laser beam at a non-absorption line as a wavelength at which the amount of light absorption by oxygen is smaller than at the absorption line; an optical system configured to irradiate a workpiece with the laser beam; and a laser control unit configured to control the wavelength-variable laser device, set the wavelength of the laser beam output from the wavelength-variable laser device to be the non-absorption line when laser processing is performed on the surface of the workpiece in gas containing oxygen, and set the wavelength of the laser beam output from the wavelength-variable laser device to be the absorption line when ozone cleaning is performed on the surface of the workpiece in gas containing oxygen.

A laser processing system includes: a wavelength-variable laser device configured to output each of a laser beam at an absorption line as a wavelength at which light is absorbed by oxygen and a laser beam at a non-absorption line as a wavelength at which the amount of light absorption by oxygen is smaller than at the absorption line; an optical system configured to irradiate a workpiece with the laser beam; and a laser control unit configured to control the wavelength-variable laser device, set the wavelength of the laser beam output from the wavelength-variable laser device to be the non-absorption line when laser processing is performed on the surface of the workpiece in gas containing oxygen, and set the wavelength of the laser beam output from the wavelength-variable laser device to be the absorption line when ozone cleaning is performed on the surface of the workpiece in gas containing oxygen.