Chromium Nitride Coated Chain Component Wear Resistance

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Solution Overview

Problem

Chromium nitride films formed by PVD methods on chain components tend to peel off easily, leading to poor wear resistance and adhesion issues, especially in high-load applications with deteriorated engine oil, and are difficult to apply to porous materials and inner surfaces.

Innovation Solution

A chromium nitride layer with a rough surface containing 0-55% iron is formed on a steel base material using a diffusion coating process, providing good adhesion and wear resistance by incorporating an intermediate layer and optimizing the Fe, Cr, and N concentration gradients, which also helps in soot removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If chromium nitride films are formed by PVD methods on chain components, then wear resistance and corrosion resistance are enhanced, but the film peels off easily and adhesion to the base material is poor

Engineering Contradiction:

Improvewear resistanceVSAvoidadhesion strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent introduces an intermediate layer between the chromium nitride film and the steel base material. This intermediate layer acts as a mediator that improves the bonding interface, allowing the hard chromium nitride coating to adhere properly to the base material while maintaining its wear-resistant properties.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite structure consisting of multiple layers: the steel base material, an intermediate layer, and the chromium nitride coating layer. This composite material approach allows each layer to perform its specific function - the base material provides structural support, the intermediate layer provides adhesion, and the chromium nitride layer provides wear and corrosion resistance.

Inventive Principle:

Principle #40Composite materials

2Reliability

If PVD methods are used to form chromium nitride films, then surface treatment is achieved, but droplets form on the surface increasing roughness and causing cracks that deteriorate wear resistance

Engineering Contradiction:

Improvesurface treatment effectivenessVSAvoidsurface roughness

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent employs a thermal spray process that can be applied rapidly to cover the entire surface, including complex geometries and porous structures. This method is more tolerant of process variations compared to PVD, producing fewer droplets and maintaining better surface quality without requiring extensive post-processing.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Duration of action of stationary object

If the chromium nitride film thickness is increased to increase life, then durability improves, but cracks form and wear resistance deteriorates

Engineering Contradiction:

Improvecomponent lifeVSAvoidwear resistance

Core Design Contradiction:

Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent applies a phosphating treatment to the steel base material before depositing the chromium nitride layer. This preliminary action creates a chemically active surface that enhances the bonding of subsequent coating layers, allowing for thicker coatings without the formation of cracks that would compromise wear resistance.

Inventive Principle:

Principle #10Preliminary action

4Area of stationary object

If chromium nitride films are formed on porous materials, then surface coverage is attempted, but it is difficult to form a film on the inner surfaces of the pores

Engineering Contradiction:

Improvesurface coverage areaVSAvoidapplicability to porous materials

Core Design Contradiction:

Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent utilizes a thermal spray process that propels coating material as a high-velocity stream, enabling the coating to penetrate into pores and reach inner surfaces of porous substrates. The fluid-like behavior of the molten or semi-molten particles allows them to follow the contours of complex geometries and deposit uniformly across the entire surface area, including within pores.

Inventive Principle:

Principle #29Pneumatics and hydraulics

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 chromium nitride layer exhibits improved wear resistance and elongation resistance over time, maintains low friction, and is less aggressive to counterparts, allowing for increased clearance distance and reduced damage from soot, thus enhancing the durability of chain components.

Implementation Method 1

a chromium nitride layer formed on an outer side of the steel base material

Methodology Applied

Scientific EffectDiffusion coating: Diffusion

Implementation Method 2

at least a surface of the chromium nitride layer that slides against other components being a rough surface with peaks and valleys

Methodology Applied

Scientific EffectFriction reduction through surface topology: Friction

Data Source

PatentUS10260596B2Chain component and chain

Publication Date: 2019.04.16 TSUBAKIMOTO CHAIN CO

AI summary

Provided are a chain component that has a simple surface treatment structure and can maintain good wear resistance over a long time, and a chain that includes the chain component and maintains good wear elongation resistance. The chain component of a power transmission chain for industrial use includes a chromium nitride layer formed on an outer side of a steel base material and containing more than 0 mass % but not more than 55 mass % iron. At least a surface of the chromium nitride layer that slides against other components is a rough surface with peaks and valleys.