Gradient Polymer Thermal Spray Coating for Slide Bearing Adhesion
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Solution Overview
Problem
Conventional laminates for slide bearings face performance limitations and adhesion issues between the PTFE sliding layer and the metallic support material, particularly due to the sintered bronze intermediate layer.
Innovation Solution
A laminate structure featuring a substrate with a heterogeneous mixture of non-fluorinated and fluorinated polymer compounds, forming a gradual concentration gradient, which includes a porous non-fluorinated polymer layer and a fluorinated polymer layer, such as PEEK and PTFE, to enhance adhesion and tribological performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sintered bronze intermediate layer is used between the metallic support and PTFE sliding layer, then the laminate structure provides self-lubricating properties, but adhesion issues occur between the PTFE sliding layer and the metallic support
Solution Approach 1:
The patent divides the intermediate layer into multiple functional zones: a first zone with higher PTFE content for adhesion and a second zone with lower PTFE content for self-lubrication. This segmentation allows each zone to optimize its specific function rather than requiring a single uniform layer to perform both functions equally well.
Solution Approach 2:
The intermediate layer is designed with spatially varying PTFE concentration, creating local quality differences. The first zone (near metal substrate) has higher PTFE content (5-20 wt%) for adhesion, while the second zone (near sliding surface) has lower PTFE content (0-10 wt%) for self-lubrication. This local optimization resolves the contradiction between adhesion and self-lubrication.
2Strength
If a heterogeneous mixture of non-fluorinated and fluorinated polymer compounds is applied, then adhesion to metal substrates is improved, but the manufacturing process complexity increases
Solution Approach 1:
The patent uses a composite material system combining non-fluorinated polymer (e.g., polyamide, polyimide) and fluorinated polymer (PTFE) in a heterogeneous mixture. This composite approach leverages the complementary properties of each material: non-fluorinated polymers provide strong metal adhesion while fluorinated polymers provide low friction and self-lubrication.
Solution Approach 2:
The patent controls the PTFE content parameter within specific ranges (5-20 wt% in first zone, 0-10 wt% in second zone) to optimize adhesion while maintaining self-lubrication. By defining specific compositional parameters rather than arbitrary mixtures, the patent simplifies manufacturing control despite using composite materials.
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 laminate exhibits improved adhesion to metal substrates and maintains consistent low friction coefficients over extended tribological testing, outperforming single-layer configurations of PEEK or PTFE, thus enhancing the durability and performance of slide bearings.
Implementation Method 1
A possible method of applying the heterogeneous mixture to the substrate is by use of a thermal spray process
Implementation Method 2
The heterogeneous mixture can be applied to the substrate in a form having a relatively high concentration of the non-fluorinated polymer compound and a relatively low concentration of the fluorinated polymer compound. Subsequent diffusion of the fluorinated polymer compound into the non-fluorinated polymer compound can occur
Data Source
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AI summary
A laminate article can include a substrate and a layer of a heterogeneous mixture of a non-fluorinated polymer compound and a fluorinated polymer compound. The laminate article can include a gradual concentration gradient along an axis perpendicular to the substrate. The gradual concentration gradient can include the change of the amount of the non-fluorinated polymer and the fluorinated polymer compound relative to the axis perpendicular to the substrate. The layer can further include at least one filler. The laminate can be applied as a bearing material