Patent ID: 11865614
Assignee: LINDE GMBH
Field: Materials, metallurgy (Chemistry)
Classification: CPC B  Y | IPC B

Claim 11:
12. An apparatus for additive manufacturing comprising
a powder delivery system comprising a storage unit for metal powder and an application device for applying the powder onto a built platform,
a heat source which is a device for generating a plasma or an arc or laser radiation for melting the powder, and
a housing with a wall,
a lift table with a built platform disposed inside the wall of the housing, wherein the wall of the housing and the built platform define a build space, and
a device for feeding gas mixture comprising Helium or Helium and Argon to the manufacturing space is connected to the build space and/or to a process chamber of the device,
wherein the gas flow to the additive manufacturing space is established by a pump connected to the manufacturing space wherein the pump is controlled by a set differential pressure, and
wherein the set differential pressure is
08 mbar to 0.16 mbar when the gas flow consists of Helium,
is 0.26 mbar to 0.34 mbar when the gas flow comprises 5 Vol.-% to 40 Vol.-% Argon and 95 Vol.-% to 60 Vol.-% Helium,
is 0.37 mbar to 0.45 mbar when the gas flow comprises 41 Vol.-% to 60 Vol.-% Argon, and 59 Vol.-% to 40 Vol.-% Helium, and
is 0.55 mbar to 0.63 mbar when the gas flow comprises 61 Vol.-% to 95 Vol.-% Argon and comprising 39 Vol.-% to 5 Vol.-% Helium.