Powder for Use in An Additive Manufacturing Method

Abstract

The invention relates to a powder for an additive manufacturing method having a d.sub.2-value of 10 m or more, a d.sub.90-value of 200 m or less and a quotient E.sub.Law/d.sub.500.8 KJ(KG*m), wherein E.sub.Law indicates the avalanche energy and d.sub.50 the average particle diameter. The invention further relates to a method for producing a component by means of additive manufacturing using the claimed powder.

Claims

1. A powder for an additive manufacturing process, comprising: a) a d.sub.2 value of 10 m or more; b) a d.sub.90 value of 200 m or less; and c) a E.sub.Law/d.sub.50 ratio of 0.8 kJ/(kg*m), whereby E.sub.Law is the avalanche energy and d.sub.50 is the mean particle diameter.

2. The powder according to claim 1, characterised in that the powder comprises an E.sub.Law/d.sub.50 value of 0.65 kJ/(kg*m) or less, in particular of 0.5 kJ/(kg*m) or less.

3. The powder according to claim 1, characterised in that the material is a metal.

4. The powder according to claim 3, characterised in that the metal is selected from the group consisting of precious metals and base metals.

5. The powder according to claim 1, characterised in that the metal is an alloy.

6. The powder according to claim 1, characterised in that the alloy is selected from the group consisting of titanium-aluminium alloys, copper-tin alloys, aluminium alloys, steel alloys, and nickel-based alloys.

7. The powder according to claim 1, whereby the metal is an amorphous metal.

8. The powder according to claim 7, whereby the amorphous metal is selected from zirconium-based amorphous metals, copper-based amorphous metals, and iron-based amorphous metals.

9. The powder according to claim 1, characterised in that at least 80% of the particles meet the following condition: 0.8d.sub.min/d.sub.max1.0, whereby d.sub.min is the minimum diameter and d.sub.max is the maximum diameter of a particle.

10. (canceled)

11. (canceled)

12. A process for the production of a component by means of additive manufacturing, comprising the steps of: a) Providing a powder comprising a d.sub.2 value of 10 m or more, a d.sub.90 value of 200 m or less, and an E.sub.Law/d.sub.50 ratio of no more than 0.80 kJ/(kg*m), and b) additive manufacturing of the component from the powder.

13. The process according to claim 12, whereby step a) comprises the following sub-steps: a1) Providing a powder; a2) sizing the powder such that the particle size distribution meets the conditions, d.sub.210 m and d.sub.90200 m; a3) selecting powders with an E.sub.Law/d.sub.50 ratio of no more than 0.80 kJ/(kg*m).

14. The process according to claim 12, whereby step b) comprises the following sub-steps: b1) Applying a layer of the powder; b2) heating at least part of the powder to the sintering and/or melting temperature by means of laser or electron radiation and subsequently cooling the heated powder.

Description

EXEMPLARY EMBODIMENTS

[0089] Powders made from various materials that can be melted and/or sintered were sized by screening (Table 1). An AS 200 unit from Retsch GmbH, Germany, was used for screening Stainless steel screens with a mesh width of 10 m, 20 m, 45 m, 63 m, and 140 m were used and approximately 100 g of powder were strained at different amplitudes for 2-5 minutes.

[0090] The d.sub.2 and d.sub.90 values of the sized powders were determined. If the values did not meet the conditions, i.e. d.sub.2 value 10 m and d.sub.90 value 200 m, after the screening, further sizing steps were undertaken until the particle size distribution was within the specified limits. A person skilled in the art knows how to appropriately select the mesh width of the various screens in order to remove particles from the powder which are outside the defined range.

[0091] If the powders met the specified conditions, i.e. d.sub.2 value 10 m and d.sub.90 value 200 m, the d.sub.50 value and the avalanche energy of the powders were measured as well and the (E.sub.Law/d.sub.50) ratio was calculated.

[0092] All powders subjected to the measurements were used to produce a cube with an edge length of 10 mm by means of selective laser melting (SLM) using a facility of ConceptLaser GmbH, Germany, model MLab. The same process parameters were used throughout (laser power: 95 W, laser speed: 150 mm/s, line distance: 0.09 mm).

[0093] The geometric density and the relative density of the components obtained were determined as described above.

[0094] The results for the powders and the component manufactured from them are summarised in Table 1.

TABLE-US-00001 TABLE 1 Summary of the characterised powders and bodies made from them. Quality of printed part: good = relative density >95%, poor ???? Relative Material Experiment d.sub.50 E.sub.Law/d.sub.50 density CuSn8 1 31 0.29 good 2 46.53 0.13 good 3 33.94 0.27 good 4 46.9 0.19 good 5 66.87 0.07 good 6 75.75 0.07 good 7 24.03 0.48 good CuSn10 8 27.18 1.23 poor 9 25.3 0.56 good Ti6Al4V 10 91.81 0.27 good 11 33.93 1.49 poor 12 39 0.33 good AlSi10Mg 13 25.11 0.72 good 14 23.85 2.55 poor AMZ4 15 87 0.31 good (ZrCuAlNb) 16 46 1.10 poor Al.sub.2O.sub.3 19 79 0.10 good ceramics 20 4 2.40 poor

[0095] It is evident from Table 1 that the mean particle diameter d.sub.50 alone is not a suitable selection criterion for suitable particles. This is evident, in particular, by comparison of the particle sizes of experiments 3, 8, and 13 in Table 1, which allow no trend in terms of the quality of the finished component to be recognised.

[0096] FIG. 1 shows, in an exemplary manner, light microscopy images of the printed components made from powders 8 and 9. As is evident, powder 9 comprises a clearly lower porosity than powder 8.