Raw material for thixomolding, method for producing raw material for thixomolding, and molded body

Patent metadata

Field	Value
Publication number	US-11148197-B2
Application number	US-201816117324-A
Country	US
Kind code	B2
Filing date	Aug 30, 2018
Priority date	Aug 31, 2017
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

A raw material for thixomolding includes a magnesium-based alloy powder which contains calcium in an amount of 0.2 mass % or more and 5 mass % or less and aluminum in an amount of 2.5 mass % or more and 12 mass % or less, wherein the magnesium-based alloy powder includes an oxide layer which has an average thickness of 30 nm or more and 100 nm or less and contains at least one of calcium and aluminum as an outermost layer. The average dendrite secondary arm spacing of crystal structures of the magnesium-based alloy powder is preferably 5 μm or less.

First claim

What is claimed is:

1. A raw material for thixomolding, comprising:
a magnesium-based alloy powder which contains calcium in an amount of 0.2 mass % or more and 5 mass % or less and aluminum in an amount of 2.5 mass % or more and 12 mass % or less,
wherein the magnesium-based alloy powder is produced by an atomization method,
an average particle diameter of the magnesium-based alloy powder is 2.0 mm or more and 5.0 mm or less,
an average aspect ratio of the magnesium-based powder that is an average of aspect ratios calculated by ((a minor axis)/(a major axis)) is 0.5 or more and 1 or less, and
the magnesium-based alloy powder includes an oxide layer which has an average thickness of 30 nm or more and 100 nm or less and contains at least one of calcium and aluminum as an outermost layer.

2. The raw material for thixomolding according to claim 1 , wherein an average dendrite secondary arm spacing of crystal structures of the magnesium-based alloy powder is 5 μm or less.

3. A molded body, comprising the raw material for thixomolding according to claim 2 .

4. The raw material for thixomolding according to claim 1 , wherein a minimum particle diameter of the magnesium-based alloy powder is 0.5 mm or more.

5. A molded body, comprising the raw material for thixomolding according to claim 4 .

6. A molded body, comprising the raw material for thixomolding according to claim 1 .

7. The raw material for thixomolding according to claim 1 , wherein an average circularity of the magnesium-based alloy powder is 0.5 or more and 1 or less.

8. A molded body, comprising the raw material for thixomolding according to claim 7 .

9. The raw material for thixomolding according to claim 1 , wherein when the oxide layer contains the calcium, a concentration of the calcium in the oxide layer is 2 times or more, and
when the oxide layer contains the aluminum, a concentration of the aluminum in the oxide layer is 2 times or more.

10. A molded body, comprising the raw material for thixomolding according to claim 9 .

11. A raw material for thixomolding, comprising:
a magnesium-based alloy powder which contains calcium in an amount of 0.2 mass % or more and 5 mass % or less and aluminum in an amount of 2.5 mass % or more and 12 mass % or less,
wherein the calcium and aluminum are segregated at a crystal grain boundary;
an average particle diameter of the magnesium-based alloy powder is 2.0 mm or more and 5.0 mm or less:
an average aspect ratio of the magnesium-based alloy powder that is an average of aspect ratios calculated by ((a minor axis)/(a major axis)) is 0.5 or more and 1 or less; and
the magnesium-based alloy powder includes an oxide layer which has an average thickness of 30 nm or more and 100 nm or less and contains a mixture of oxides of magnesium, calcium, and aluminum as an outermost layer; and

at locations of a surface of the powder where the crystal grain boundary appears, the thickness of the oxide layer is greater than at locations of the surface of the powder where the crystal grain boundary does not appear.

Assignees

• Seiko Epson Corp

Inventors

• Hideshima Yasutoshi
• Nakamura Hidefumi
• Otaka Hiroyoshi

Classifications

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title

• B22F1/05

  Metallic powder characterised by the size or surface area of the particles · CPC title

• B21J5/00

  Methods for forging, hammering, or pressing (for working sheet-metal or metal tubes, rods, or profiles B21D; for working wire B21F); Special equipment or accessories therefor · CPC title

• B22D17/2061

  using screws · CPC title

• B22F2009/0812

  Pulverisation with a moving liquid coolant stream, by centrifugally rotating stream · CPC title