Method for manufacturing sintered component, sintered component, and drill

Patent metadata

Field	Value
Publication number	US-11305347-B2
Application number	US-202016922287-A
Country	US
Kind code	B2
Filing date	Jul 7, 2020
Priority date	Dec 12, 2014
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

Provided is a method for manufacturing a sintered component, which can suppress occurrence of edge chipping when a through-hole is formed in a powder-compact green body and also has a good productivity. The method for manufacturing a sintered component includes a molding step of press-molding a raw material powder containing a metal powder and thus fabricating a powder-compact green body; a drilling step of forming a hole in the powder-compact green body using a drill; a sintering step of sintering the powder-compact green body after drilling, wherein the drill used for drilling has a circular-arc shaped cutting edge on a point portion thereof.

First claim

The invention claimed is:

1. A drill for drilling a powder-compact green body, comprising:
a circular arc-shaped cutting edge only on a point portion thereof,
wherein the powder-compact green body is fabricated by press-molding a raw material powder containing a metal powder and a powder lubricant,
wherein the powder-compact green body is formed before a heat treatment,
wherein the lubricant is served as a lubricant for the drill when the powder-compact green body is drilled to reduce a cutting resistance,
wherein a radius of the circular arc defining the cutting edge is a radius of the drill,
wherein a length of the point portion along an axial direction of the drill is equal to the radius of the circular arc,
wherein the cutting edge cuts the powder-compact green body to form a hole in the powder-compact green body, and
wherein a shape of an inner circumferential surface of the hole is a satin finish shape.

2. The drill according to claim 1 , wherein the drill is configured so that a rake angle of the cutting edge is more than 0° and 10° or less.

3. The drill according to claim 2 , wherein the drill is configured so that a circular arc defining the cutting edge has a central angle of 135° or more and 180° or less.

4. The drill according to claim 2 , wherein the rake angle is an angle between a center axis of the drill and the cutting edge.

5. The drill according to claim 1 , wherein a feed rate of the drill is 200 mm/min or more.

6. The drill according to claim 1 , wherein content of the lubricant is set to 0.1 mass % or more and 2 mass % or less assuming that the raw material powder is 100 mass %.

7. The drill according to claim 1 , wherein the point portion is from an apex of the cutting edge to an outer corner.

8. The drill according to claim 1 , wherein a feed amount of the drill is 0.1 mm/rev or more.

Assignees

• Sumitomo Electric Sintered Alloy Ltd
• Nikken Tool Co Ltd

Inventors

• Sonoda Yasunori
• Take Ryota
• Matsumoto Fumihiro
• SUGIMOTO Tsuguru

Classifications

• C22C38/00 Primary

  Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) · CPC title

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title

• B23B2251/18

  Configuration of the drill point · CPC title

• B22F5/10

  of articles with cavities or holes, not otherwise provided for in the preceding subgroups · CPC title

• B22F3/162 Primary

  Machining, working after consolidation · CPC title