Additive manufacturing method and powder

Patent metadata

Field	Value
Publication number	US-2018010221-A1
Application number	US-201515506007-A
Country	US
Kind code	A1
Filing date	Sep 10, 2015
Priority date	Sep 10, 2014
Publication date	Jan 11, 2018
Grant date	—

Abstract

A method of manufacturing a part including selective laser melting of a powder including a steel alloy containing, by weight, 16% to 19% chromium and 12.2% to 13.5% nickel, wherein the powder is substantially non-magnetic.

First claim

1 . A method of manufacturing a part comprising selective laser melting of a powder comprising a steel alloy containing, by weight, 16% to 19% chromium and 12.2% to 13.5% nickel, wherein the powder is substantially non-magnetic.

2 . A method according to claim 1 , wherein less than 2% by volume of the steel alloy is in the ferrite phase.

3 . A method according to claim 2 , wherein less than 1.5% by volume of the steel alloy is in the ferrite phase.

4 . A method according to claim 3 , wherein less than 1% by volume of the steel alloy is in the ferrite phase.

5 . A method according to claim 4 , wherein less than 0.5% by volume of the steel alloy is in the ferrite phase.

6 . A method according to claim 4 , wherein substantially 0% by volume of the steel alloy is in the ferrite phase.

7 . A method according to claim 1 , wherein the powder has a hall flow of less than 23 s/50 g.

8 . A method according to claim 7 , wherein the powder has a hall flow of less than 22 s/50 g.

9 . A method according to claim 1 , wherein the alloy contains, by weight, 12.2% to 13.2% nickel.

10 . A method according to claim 9 , wherein the alloy contains, by weight, 12.5% to 12.9% nickel.

11 . A method according to claim 1 , wherein the alloy contains, by weight, less than 1% manganese.

12 . A method according to claim 11 , wherein the alloy contains, by weight, less than 0.7% manganese.

13 . A method according to claim 12 , wherein the alloy contains, by weight, less than 0.5% manganese.

14 . A method according to claim 11 , wherein the alloy contains, by weight, less than 0.01% sulphur.

15 . A method according to claim 1 , wherein the alloy contains, by weight, 0.05% to 0.4% copper.

16 . A method according to claim 1 , wherein at least 98% by volume of the alloy is in the austenite phase.

17 . A method according to claim 1 , wherein the powder has been formed by nitrogen gas atomisation.

18 . A method according to claim 1 , wherein the powder is atomised from an ingot produced by vacuum arc remelting (VAR).

19 . A method according to claim 1 , wherein the powder contains at least 90% by weight particles having a size, as measured by a laser diffraction particle size analyser, below 45 μm.

20 . A method according to claim 19 , wherein the powder contains at least 94% by weight particles having a size, as measured by the laser diffraction particle size analyser, below 45 μm.

21 . A method according to claim 20 , wherein the powder contains at least 96% by weight particles having a size, as measured by the laser diffraction particle size analyser, below 45 μm.

22 . A method according to claim 1 , wherein the powder contains less than 2% by weight particles having a size, as measured by a laser diffraction particle size analyser, below 15 μm.

23 . A method according to claim 22 , wherein the powder contains less than 1% by weight particles having a size, as measured by the laser diffraction particle size analyser, below 15 μm.

24 . A powder container arranged to be attached to an additive manufacturing machine, the powder container containing powder comprising a steel alloy containing, by weight, 16% to 19% chromium and 12.2% to 13.5% nickel, wherein the powder is substantially non-magnetic.

25 . A method of manufacturing powder for use in additive manufacturing apparatus comprising atomising a molten steel alloy containing, by weight, 16% to 19% chromium and 12.2% to 13.5% nickel such that less than 2% by volume of the steel alloy is in the ferrite phase and filling a container arranged to be attached to an additive manufacturing machine with the powder.

26 . A method according to claim 25 , comprising nitrogen atomising the molten steel alloy.

27 . A method according to claim 25 , comprising carrying out vacuum arc remelting (VAR) on the steel alloy before atomisation.

Assignees

• Renishaw Plc

Inventors

• Aswathanarayanaswamy Ravi Guttamindapalli
• Sheykh-Poor Hossein
• Jerrard Peter George Eveleigh

Classifications

• B22F10/36

  of energy beam parameters · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B22F10/366

  Scanning parameters, e.g. hatch distance or scanning strategy · CPC title

• B22F10/32

  of the atmosphere, e.g. composition or pressure in a building chamber · CPC title

• B22F10/34

  of powder characteristics, e.g. density, oxidation or flowability · CPC title