Manufacturing method of sintered alloy, compact for sintering, and sintered alloy

Patent metadata

Field	Value
Publication number	US-9950369-B2
Application number	US-201715421787-A
Country	US
Kind code	B2
Filing date	Feb 1, 2017
Priority date	Feb 4, 2016
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

Mixed powder that contains first hard particles, second hard particles, graphite particles, and iron particles is used to manufacture a sintered alloy. The first hard particle is a Fe—Mo—Cr—Mn based alloy particle, the second hard particle is a Fe—Mo—Si based alloy particle. The mixed powder contains 5 to 50 mass % of the first hard particles, 1 to 8 mass % of the second hard particles, and 0.5 to 1.0 mass % of the graphite particles when total mass of the first hard particles, the second hard particles, the graphite particles, and the iron particles is set as 100 mass %.

First claim

What is claimed is:

1. A manufacturing method of a sintered alloy comprising:
pressing mixed powder that contains first hard particles, second hard particles, graphite particles, and iron particles into a sintered-alloy compact; and
sintering the sintered-alloy compact while diffusing carbons in the graphite particles of the sintered-alloy compact into the first hard particles, the second hard particles, and the iron particles, wherein
the first hard particles contain 10 to 50 mass % of Mo, 3 to 20 mass % of Cr, 2 to 15 mass % of Mn, 1 mass % or less of C, and a remainder including Fe and inevitable impurities when the first hard particles have 100 mass %,
the second hard particles contain 60 to 70 mass % of Mo, 2 mass % or less of Si, and a remainder including Fe and inevitable impurities when the second hard particles have 100 mass %, and
the mixed powder contains 5 to 50 mass % of the first hard particles, 1 to 8 mass % of the second hard particles, and 0.5 to 1.0 mass % of the graphite particles when total mass of the first hard particles, the second hard particles, the graphite particles, and the iron particles is set as 100 mass %.

2. The manufacturing method according to claim 1 , wherein
a particle diameter of the second hard particle falls within a range of 75 μm and smaller.

3. The manufacturing method according to claim 1 , wherein
the sintered-alloy compact is heated and sintered at 1050 to 1250° C.

4. The manufacturing method according to claim 1 , wherein
the first hard particles contain 25 to 35 mass % of Mo, 5 to 10 mass % of Cr, 2 to 10 mass % of Mn, and 1 mass % or less of C when the first hard particles have 100 mass %.

5. The manufacturing method according to claim 1 , wherein
the remainder of the first hard particles and the remainder of the second hard particles are Fe and the inevitable impurities.

6. A compact for sintering comprising:
first hard particles that contain 10 to 50 mass % of Mo, 3 to 20 mass % of Cr, 2 to 15 mass % of Mn, 1 mass % or less of C, and a remainder including Fe and inevitable impurities when the first hard particles have 100 mass %;
second hard particles that contain 60 to 70 mass % of Mo, 2 mass % or less of Si, and a remainder including Fe and inevitable impurities when the second hard particles have 100 mass %;
graphite particles; and
iron particles, wherein
the first hard particles occupy 5 to 50 mass %, the second hard particles occupy 1 to 8 mass %, and the graphite particles occupy 0.5 to 1.0 mass % when total mass of the first hard particles, the second hard particles, the graphite particles, and the iron particles is set as 100 mass %.

7. The compact for sintering according to claim 6 , wherein
a particle diameter of the second hard particle falls within a range of 75 μm and smaller.

8. The compact for sintering according to claim 6 , wherein
the first hard particles contain 25 to 35 mass % of Mo, 5 to 10 mass % of Cr, 2 to 10 mass % of Mn, and 1 mass % or less of C when the first hard particles have 100 mass %.

9. The compact for sintering according to claim 6 , wherein
the remainder of the first hard particles and the remainder of the second hard particles are Fe and the inevitable impurities.

10. A sintered alloy obtained by sintering a compact comprising:
first hard particles that contain 10 to 50 mass % of Mo, 3 to 20 mass % of Cr, 2 to 15 mass % of Mn, 1 mass % or less of C, and a remainder including Fe and inevitable impurities when the first hard particles have 100 mass %;
second hard particles that contain 60 to 70 mass % of Mo, 2 mass % or less of Si, and a remainder including Fe and inevitable impurities when the second hard particles have 100 mass %;
graphite particles; and
iron particles, wherein
the first hard particles occupy 5 to 50 mass %, the second hard particles occupy 1 to 8 mass %, and the graphite particles occupy 0.5 to 1.0 mass % when total mass of the first hard particles, the second hard particles, the graphite particles, and the iron particles is set as 100 mass %, and
in the sintered alloy, carbon is diffused into the hard particles and the iron particles.

Assignees

• Toyota Motor Co Ltd
• Fine Sinter Co Ltd
• Sanyo Special Steel Co Ltd
• Sanyo Special Steel Co Ltd

Inventors

• Shinohara Nobuyuki
• Ando Kimihiko
• Ueda Yoshihisa
• Yoshida Yusaku
• Sugimoto Masaru
• Sawada Toshiyuki
• Fukumoto Shingo

Classifications

• B22F1/09

  Mixtures of metallic powders · CPC title

• B22F1/12

  Metallic powder containing non-metallic particles (containing lubricating or binding agents or organic material B22F1/10) · CPC title

• B22F3/02 Primary

  Compacting only · CPC title

• C22C33/0285 Primary

  with Cr, Co, or Ni having a minimum content higher than 5% · CPC title

• B32B15/01

  all layers being exclusively metallic {(making layered metal workpieces by pressure cladding B23K20/22; making coatings with a metallic material characterised by its composition C23C30/00)} · CPC title