Laminated Hard Carbon Piston Ring Wear Resistance
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Solution Overview
Problem
Existing piston ring technologies face challenges in achieving effective wear resistance and adhesion due to complex film formation processes and instability of high hardness layers, with inadequate study on the relationship between amorphous hard carbon layers and their properties.
Innovation Solution
A piston ring with a laminated hard carbon film comprising a lower, middle, and upper layer, where the lamination pitches and sp2/sp3 component ratios are specifically controlled to enhance adhesion and wear resistance, and the manufacturing method involves physical vapor deposition with alternately applied bias voltages to achieve a smooth surface with reduced macroparticles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a multi-layered structure with different hardness layers is formed by sputtering and ion plating, then wear resistance is improved, but the film formation process becomes complex
Solution Approach 1:
The invention changes the film formation parameters by using only ion plating process with controlled deposition conditions to form a hard carbon film with specific sp2/sp3 hybridization ratio and lamination structure, eliminating the need for alternating sputtering and ion plating processes while achieving comparable or superior wear resistance
Solution Approach 2:
The invention creates a composite hard carbon film with specific sp2-sp3 hybridization structure and lamination pattern that combines the benefits of different material phases within a single material system, achieving wear resistance without requiring multiple alternating material layers
2Strength
If a high hardness layer with thickness of 5 nm to 90 nm is formed, then initial hardness is improved, but the layer cannot always be maintained making it difficult to maintain wear resistance
Solution Approach 1:
The invention changes the critical parameters of sp2/sp3 hybridization ratio and lamination pitch to create a hard carbon film that maintains optimal balance between hardness and toughness, preventing layer instability and delamination while maintaining wear resistance over extended service life
Solution Approach 2:
The lamination structure with specific pitch acts as a pre-designed stress distribution mechanism that prevents crack propagation and layer delamination before they can occur, maintaining layer stability under operational stresses
3Reliability
If amorphous hard carbon layers are formed with controlled composition, then adhesion and hardness are improved, but the relationship between layer structure and wear resistance had not been adequately studied
Solution Approach 1:
The invention systematically varies and controls the sp2/sp3 hybridization ratio and lamination pitch parameters to establish their specific relationships with wear resistance performance, filling the knowledge gap about how amorphous hard carbon layer structure affects wear properties
Solution Approach 2:
The invention establishes a feedback mechanism where the sp2/sp3 ratio and lamination pitch are controlled based on their measured impact on wear resistance, creating a knowledge base that guides subsequent film formation to achieve optimal performance
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 results in a piston ring with improved adhesion and wear resistance, simplifying the film formation process and eliminating the need for additional surface smoothing treatments, thereby reducing costs and maintaining wear resistance effectively.
Implementation Method 1
the manufacturing method involves physical vapor deposition with alternately applied bias voltages
Implementation Method 2
the high hardness layer is formed by ion plating
Data Source
AI summary
To provide a piston ring comprising a hard carbon film that is easy to form and exhibits excellent adhesion and wear resistance, and a manufacturing method therefor. The above-described problem is solved by means of a piston ring comprising a hard carbon film 50 formed on at least an outer peripheral sliding surface 11 of a piston ring base material 1, wherein the hard carbon film 50 is a laminated film comprising a plurality of layers, including an upper layer 5 with a lamination pitch within a range of 3 nm to 50 nm inclusive, a middle layer 4 with a lamination pitch less than that of the upper layer 5, and a lower layer 3 with a lamination pitch within the same range as that of the upper layer 5 and greater than that of the middle layer 4. This hard carbon film 50 may be configured to have an sp2 component ratio within a range of 35% to 80% inclusive, measured in a TEM-EELS spectrum formed by combining electron energy loss spectroscopy (EELS) with a transmission electron microscope (TEM), and a hydrogen content within a range of 0.1 atom % to 5 atom % inclusive.