Method for manufacturing sintered component, sintered component, and drill

Patent metadata

Field	Value
Publication number	US-11325186-B2
Application number	US-201515535263-A
Country	US
Kind code	B2
Filing date	Dec 8, 2015
Priority date	Dec 12, 2014
Publication date	May 10, 2022
Grant date	May 10, 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 method for manufacturing a sintered component, comprising:
a molding step of press-molding a raw material powder containing a metal powder and a powder lubricant and thus fabricating a powder-compact green body in which the lubricant is dispersed;
a drilling step of forming a hole in the powder-compact green body using a drill, the hole having an inner circumferential surface whose shape is a satin finish shape; and
a sintering step of sintering the powder-compact green body after drilling,
wherein the powder-compact green body is formed before a heat treatment,
wherein the raw material powder contains no organic binder,
wherein the drill used for drilling has a circular-arc shaped cutting edge on a point portion thereof,
wherein the drill is configured so that a rake angle of the cutting edge is more than 0° and 10° or less,
wherein the rake angle of the cutting edge is an angle between a center axis of the drill and the cutting edge, and
wherein the cutting edge cuts the powder compact green body to form the hole.

2. The method according to claim 1 , 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.

3. The method according to claim 1 , wherein the drilling step has a feed rate of 200 mm/min or more.

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

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

• B22F5/106

  Tube or ring forms · CPC title

• B22F5/06

  of threaded articles, e.g. nuts · CPC title

• B23B2251/082

  Curved cutting edges · CPC title

• B22F3/24

  After-treatment of workpieces or articles {(B22F3/1146 takes precedence)} · CPC title