Powder for additive manufacturing, additively manufactured body, method for producing additively manufactured body, and method for producing metal sintered body
A powder for additive manufacturing, which is a powder to be used in a three-dimensional additive manufacturing method, including a plurality of coated particles containing metal particles, and resin coating films that cover the metal particles and contain a caking additive, wherein 0.0001≤t/D50≤0.0010 in which t is an average thickness of the resin coating films and D50 is an average particle diameter of the metal particles.
1. A powder for additive manufacturing, which is a powder to be used in a three-dimensional additive manufacturing method, comprising:
a plurality of coated particles containing
metal particles, and
resin coating films that cover the metal particles and contain a caking additive, wherein
the caking additive includes polyisobutylene,
an average molecular weight of the polyisobutylene is 5000 or more and 500000 or less,
0.0001≤t/D50≤0.0010 in which t is an average thickness of the resin coating films and D50 is an average particle diameter of the metal particles, and
a specific surface area of each of the metal particles is 0.05 m 2 /g or more and 0.50 m 2 /g or less.
2. The powder for additive manufacturing according to claim 1 , wherein the average particle diameter D50 of the metal particles is 0.1 μm or more and 5.0 μm or less.
3. The powder for additive manufacturing according to claim 1 , wherein the resin coating films have hydrophobicity.
4. The powder for additive manufacturing according to claim 1 , wherein the resin coating films contain a surfactant.
5. The powder for additive manufacturing according to claim 1 , wherein the caking additive has a glass transition temperature of room temperature or lower.
6. A method for producing an additively manufactured body, which is a method for producing the additively manufactured body by a three-dimensional additive manufacturing method, comprising:
a powder layer formation step of forming a powder layer using a powder for additive manufacturing including a plurality of coated particles containing metal particles and resin coating films that cover the metal particles and contain a caking additive, wherein
the caking additive includes polyisobutylene,
an average molecular weight of the polyisobutylene is 5000 or more and 500000 or less, and
0.0001≤t/D50≤0.0010 in which t is an average thickness of the resin coating films and D50 is an average particle diameter of the metal particles; and
a caking additive dissolution step of dissolving the caking additive in the powder layer by supplying a solvent to a supply area of the powder layer so as to join the metal particles to one another in the supply area, thereby obtaining a binded body, wherein
a specific surface area of each of the metal particles is 0.05 m 2 /g or more and 0.50 m 2 /g or less.
7. A method for producing a metal sintered body, comprising:
a degreasing step of subjecting an additively manufactured body produced by the method for producing the additively manufactured body according to claim 6 to a degreasing treatment, thereby obtaining a degreased body; and
a firing step of firing the degreased body, thereby obtaining a metal sintered body.
8. The powder for additive manufacturing according to claim 1 , wherein an average molecular weight of the caking additive is 5000 or more and 500000 or less.