Low-Phosphorus Electroless Nickel Plating for Compressor Sliding Members

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Solution Overview

Problem

Existing sliding members for compressors, such as vane compressors, face challenges in achieving both hardness and toughness while avoiding the adhesion of Ni particles and maintaining cost-effectiveness, as conventional hard nickel-phosphorus plating compromises on toughness when hardness is increased and is expensive due to the use of Ni-Co-P or Ni-P-B plating.

Innovation Solution

An electroless low-phosphorus nickel plating layer with a non-heat treated Ni crystallite diameter of 8 nm to 11 nm, containing 1.0 to 2.0 mass% phosphorus and no boron or cobalt, applied as a barrel plating film on an aluminum alloy base material, providing a balance of hardness and toughness without Ni particle adhesion and at a lower cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If heat treatment is applied to increase hardness of Ni-P plating, then hardness is improved, but toughness decreases

Engineering Contradiction:
ImprovehardnessVSAvoidtoughness
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention changes the phosphorus content parameter to a specific range (1.0-2.0 mass%) and controls the crystallite diameter (8-11 nm) to achieve the desired balance between hardness and toughness without heat treatment. This parameter optimization allows the plating to maintain both hardness and toughness simultaneously.

Inventive Principle:
Principle #35Parameter changes

2Strength

If Ni-Co-P or Ni-P-B plating is used to achieve both hardness and toughness, then performance is improved, but cost increases

Engineering Contradiction:
Improvehardness and toughnessVSAvoidcost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention uses a simple Ni-P plating composition without expensive alloying elements like cobalt or boron. By optimizing the phosphorus content and crystallite size, the patent achieves the required performance with a cheaper, simpler plating formulation, eliminating the need for costly Ni-Co-P or Ni-P-B compositions.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Strength

If conventional Ni-P plating is applied, then hardness is achieved, but Ni particles adhere to the surface requiring post-processing

Engineering Contradiction:
ImprovehardnessVSAvoidpost-processing steps
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention changes the phosphorus content to a low range (1.0-2.0 mass%) and controls the crystallite diameter (8-11 nm) to prevent Ni particle adhesion. This parameter optimization eliminates the formation of adherent Ni particles on the surface, removing the need for post-processing removal steps.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution achieves a Vickers hardness of 650 to 750 Hv and improved scratch strength, inhibits Ni particle adhesion, and reduces production costs by using an inexpensive plating solution, ensuring both hardness and toughness are met without the need for heat treatment or expensive alloying elements.

Implementation Method 1

an electroless nickel plating layer containing phosphorus which is formed on a surface of the base material

Methodology Applied
Scientific EffectElectroless plating: Electroplating

Data Source

PatentEP3460096A1Sliding member for compressor
Publication Date: 2019.03.27 VALEO ELECTRIFICATION
  • EP3460096A1 patent drawingFigure 1
  • EP3460096A1 patent drawingFigure 2
  • EP3460096A1 patent drawingFigure 3

AI summary

A sliding member for a compressor according to the present disclosure is a sliding member for a compressor including a base material formed of an aluminum alloy, and an electroless nickel plating layer containing phosphorus which is formed on a surface of the base material, in which in the electroless nickel plating layer, a phosphorus (P) content is 1.0 mass% to 2.0 mass%, a boron (B) content is 0 mass% to 0.01 mass%, and a cobalt (Co) content is 0 mass% to 0.01 mass%, and in which the electroless nickel plating layer is a non-heat treated layer, the electroless nickel plating layer contains Ni crystallites, and a crystallite diameter of the crystallites measured by an X-ray diffraction method is 8 nm to 11 nm.