Impeller for rotary machine, compressor, supercharger, and method for producing impeller for rotary machine

Patent metadata

Field	Value
Publication number	US-11015250-B2
Application number	US-201515541879-A
Country	US
Kind code	B2
Filing date	Mar 17, 2015
Priority date	Mar 17, 2015
Publication date	May 25, 2021
Grant date	May 25, 2021

Abstract

An impeller for a rotary machine includes a base material of the impeller made of Al or an Al alloy. A surface layer for the impeller is formed by an electroless plating layer with a Ni—P based alloy and an under layer disposed between the base material and the surface layer, the under layer having a smaller Vickers hardness than the surface layer.

First claim

The invention claimed is:

1. An impeller for a rotary machine, comprising:
a base material of the impeller comprising Al or an Al alloy;
a surface layer for the impeller formed by an electroless plating layer comprising a Ni—P based alloy; and
an under layer disposed between the base material and the surface layer, the under layer having a smaller Vickers hardness than the surface layer,
wherein the under layer comprises a plating layer containing Ni,
wherein the plating layer serving as the under layer comprises a Ni—P based alloy having an amorphous structure, the Ni—P based alloy having a P content rate of not less than 10 wt % and not more than 13 wt % in the under layer.

2. The impeller for a rotary machine according to claim 1 , wherein the Ni plating layer serving as the under layer is an electrolytic plating layer having a Vickers hardness of not more than 350 HV.

3. A compressor comprising a compressor impeller which comprises an impeller according to claim 1 .

4. A supercharger, comprising:
a compressor according to claim 3 ; and
a turbine for driving the compressor.

5. The supercharger according to claim 4 ,
wherein the compressor is disposed in an intake passage of an internal combustion engine,
wherein the turbine is configured to be driven by exhaust gas from the internal combustion engine, and
wherein the supercharger is configured such that a part of the exhaust gas is circulated to the intake passage at an upstream side of the compressor.

6. A method of producing an impeller for a rotary machine, the method comprising:
a step of forming an under layer comprising a plating layer containing Ni on a base material of the impeller comprising Al or an Al alloy so as to cover the base material; and
a step of forming an electroless plating layer comprising a Ni—P based alloy on the under layer as an outermost layer of the impeller,
wherein the under layer has a smaller Vickers hardness than the outermost layer, and
wherein the plating layer serving as the under layer comprises a Ni—P based alloy having an amorphous structure, the Ni—P based alloy having a P content rate of not less than 10 wt % and not more than 13 wt % in the under layer.

Assignees

• Mitsubishi Heavy Ind Engine & Turbocharger Ltd

Inventors

• Watanabe Daigo
• Arai Takashi
• Yamaguchi Hideki
• Murono Wataru
• Torigoe Taiji
• Yamada Masahiro

Classifications

• F02M26/04 Primary

  with a single turbocharger · CPC title

• F05D2300/173

  Aluminium alloys, e.g. AlCuMgPb · CPC title

• F05D2300/121

  Aluminium · CPC title

• F05D2300/604

  Amorphous · CPC title

• F05D2300/5021

  Expansivity · CPC title