Composite Plastic Member with Alternating Chromium Coatings
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Solution Overview
Problem
Conventional camera mounts made of brass are costly and not suitable for mass production, requiring a more affordable and durable material with high hardness, wear resistance, sliding performance, conductivity, and aesthetic appeal for camera systems.
Innovation Solution
A composite plastic member with a soft plastic substrate coated with alternately stacked chromium and chromium nitride layers, using the Filtered Cathodic Vacuum Arc Method (FCVA) and sputtering to achieve high hardness, wear resistance, and conductivity, while maintaining mechanical strength and aesthetic appeal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If brass is used for manufacturing camera mounts, then high hardness and wear resistance are achieved, but production cost increases and mass production becomes difficult
Solution Approach 1:
The patent uses a composite structure consisting of a plastic substrate combined with chromium and chromium nitride coating layers. This composite material approach provides the hardness and wear resistance of metal chromium layers while using inexpensive plastic as the base material, enabling mass production at low cost while maintaining high surface hardness through the PVD-coated chromium layers.
2Ease of manufacture
If plastic is used as mount material, then production cost decreases and mass production becomes feasible, but hardness and wear resistance deteriorate
Solution Approach 1:
The invention creates a composite structure where a plastic substrate is coated with multiple layers of chromium and chromium nitride using PVD technology. The plastic provides low-cost mass production capability, while the chromium coating layers provide the necessary surface hardness and wear resistance, combining the advantages of both materials.
Solution Approach 2:
The patent applies physical vapor deposition (PVD) coating technology to deposit chromium and chromium nitride layers on the plastic substrate. This parameter change in the surface treatment process transforms the soft plastic surface into a hard, wear-resistant coating surface with high hardness and excellent sliding performance.
3Duration of action of stationary object
If chromium coating is applied on plastic substrate, then wear resistance improves, but adhesion between coating and substrate deteriorates
Solution Approach 1:
The patent divides the coating structure into multiple alternating layers of chromium and chromium nitride. This segmented multi-layer structure improves adhesion by creating intermediate bonding layers and stress distribution, preventing delamination while maintaining high surface hardness and wear resistance of the chromium layers.
Solution Approach 2:
The alternating chromium and chromium nitride layers form a composite coating structure where each layer contributes different properties. The chromium layers provide hardness and wear resistance, while the chromium nitride layers enhance adhesion to the plastic substrate and provide stress relief, solving the adhesion problem.
4Reliability
If multiple chromium layers are stacked to improve adhesion, then adhesion improves, but manufacturing complexity increases
Solution Approach 1:
The patent segments the coating into alternating chromium and chromium nitride layers, where the chromium nitride layers serve as adhesion promoters between the plastic substrate and chromium layers. This segmented structure systematically improves adhesion through chemical bonding while the regular alternating pattern simplifies the manufacturing process compared to random multi-layer stacking.
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 composite plastic member provides improved adhesion, mechanical strength, wear resistance, and sliding performance, while being cost-effective and suitable for mass production, with the chromium nitride layers enhancing toughness and conductivity.
Implementation Method 1
a nitrogen-containing chromium film is formed on a substrate made of steel, etc. For example, Japanese Patent Application Laid-open No. 2010-242135 discloses a nitrogen-containing chromium film member for a sliding component of an automobile, etc.
Implementation Method 2
a composite plastic member with a soft plastic substrate coated with alternately stacked chromium and chromium nitride layers, using the Filtered Cathodic Vacuum Arc Method (FCVA) and sputtering
Data Source
AI summary
A composite plastic member includes a first stacked body comprised of a plurality of chromium layers stacked on a plastic substrate; and a second stacked body comprised of a plurality of chromium nitride layers stacked on the first stacked body. Each of the first and second stacked bodies is formed such that a lower-hardness layer having a lower hardness than upper and lower layers which contact with and sandwich the lower-hardness layer therebetween and a higher-hardness layer having a higher hardness than upper and lower layers which contact with and sandwich the higher-hardness layer therebetween are alternately stacked in a stacking direction; and a thickness of a higher-hardness chromium nitride layer is not more than 40% of a thickness of a lower-hardness chromium nitride layer in the second stacked body. The composite plastic member has high wear resistance and satisfactory sliding performance, and the conductivity and excellent outer appearance.