The invention relates to a method for making metallic and/or non-metallic products 2, in particular dental products, by freeform sintering and/or melting, in which the products 2 are fabricated layer by layer from a material 5 that is applied layer by layer by means of a computer-controlled high-energy beam 7, in particular a laser or electron beam In order to reduce production times, beam 7 irradiates predetermined positions P 1 to P 6 of a layer of a material 5 a plurality of time, namely m times, where m is a whole integer greater than 1 Each of said positions P 1 to P 6 is initially heated during the first irradiation to a temperature below the melting point T melt of the material 5, and during the mth irradiation to a temperature above said melting point and is completely melted over the entire thickness of the layer in such a way that the material ( 5 ) fuses at said position to the layer thereunder The invention also relates to an apparatus for performing said method

Method and apparatus for making products by sintering and/or melting

https://hal.archives-ouvertes.fr/hal-02387460/document

Reduction of the hot cracking sensitivity of CM-247LC superalloy processed by laser cladding using induction preheating

A method of welding age-hardenable aluminum alloys to improve strength properties in the heat affected zone and the weld zone, the method comprising the steps of providing precipitation hardenable aluminum alloy members to be welded and subjecting said members to a first aging step for times and temperatures to generated strengthening precipitates. Thereafter, the aged members are welded to provide a welded assembly having a weld zone. The welded members are subjected to a second aging step to reprecipitate strengthening precipitates dissolved in the weld zone.

Welded aluminum alloy structure

A process is provided for crack-free welding a nickel based single crystal superalloy article containing at least 5 weight % total of Al and Ti The process comprises: melting an article surface to be welded and a filler alloy with an energy source, preferably a laser, wherein the filler alloy is a composition of a nickel based single crystal superalloy except that the total of Al and Ti is reduced below 5 wt %; allowing the melted article surface and filler alloy to solidify to form a bead of deposit; providing a plurality of beads of adjacent deposits covering the article surface to be welded; and remelting the adjacent beads of deposits with the energy source to provide vertically oriented crystal growth in the deposits

Welding single crystal articles

A method is provided for repairing Z-notch wear surfaces on low pressure gas turbine engine turbine blades. The method is directed to turbine blades made of superalloy Inconel 713. Powdered Inconel 713 is welded to the Z-notch wear surface by directing an Nd:YAG laser beam upon the material. The laser beam is focused and traverses the wear surface in a stich-like pattern. The method allows Inconel 713 turbine blades to be repaired with the same material in a manner that does not generate cracking in the matrix material.

Laser powder fusion repair of Z-notches with inconel 713 powder

A process is provided for welding a nickel or cobalt based superalloy article to minimize cracking by preheating the entire weld area to a maximum ductility temperature range, maintaining such temperature during welding and solidification of the weld, raising the temperature for stress relief of the superalloy, then cooling at a rate effective to minimize gamma prime precipitation.

Kevin Updegrove

Papers

Welding superalloy articles

Welding method of superalloy articles