Patterned Coating for Substrate Flexural Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Coatings applied to substrates, such as glass, often reduce the average flexural strength of the substrate due to inherent mechanical attributes, leading to a need for preventing crack formation and maintaining strength retention.
Innovation Solution
A patterned coating with a bimodal distribution of thickness and surface topography is applied, which includes regions of varying tensile stress and strain, reducing stress concentration and providing strain relief to prevent crack formation and maintain substrate strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a coating is applied to the substrate surface, then functional properties (hardness, conductivity, optical properties) are improved, but the average flexural strength of the substrate is reduced
Solution Approach 1:
The coating is divided into multiple discrete islands or peaks rather than forming a continuous film. This segmentation prevents stress concentration that would occur in a continuous coating, allowing the substrate to maintain its flexural strength while still providing functional properties where the coating is present.
Solution Approach 2:
The coating is applied non-uniformly with varying thickness across different regions. Thicker regions provide enhanced functional properties while thinner or absent regions allow stress relief, creating local variations that balance functionality with mechanical strength retention.
2Reliability
If a thin film coating is applied to enhance functional properties, then coating functionality is improved, but crack formation is more likely due to stress concentration
Solution Approach 1:
The coating is segmented into discrete islands that are separated by gaps or valleys in the substrate. This segmentation prevents the formation of continuous crack paths through the coating, as cracks must navigate around the discrete coated regions rather than propagating through a continuous film.
Solution Approach 2:
The patterned coating structure is designed in advance to provide stress relief mechanisms. The valleys or gaps between coated peaks act as pre-designed stress relief zones that absorb and distribute stresses before they can concentrate and initiate cracks in the coating.
3Stability of the object's composition
If a continuous coating is applied to provide uniform functional properties, then coating uniformity is improved, but stress concentration increases leading to reduced substrate strength
Solution Approach 1:
Instead of uniform coating thickness, the invention employs local variations in coating thickness with thicker peaks and thinner or absent valleys. This local quality approach provides functional properties where needed while creating stress relief zones that prevent overall stress concentration.
Solution Approach 2:
The coating transitions from a two-dimensional continuous plane to a three-dimensional patterned structure with peaks and valleys. This dimensional change introduces vertical relief that allows stress to be distributed through the thickness variation rather than concentrated in a single plane.
Data Source
AI summary
Embodiments of a article including include a substrate and a patterned coating are provided. In one or more embodiments, when a strain is applied to the article, the article exhibits a failure strain of 0.5% or greater. Patterned coating may include a particulate coating or may include a discontinuous coating. The patterned coating of some embodiments may cover about 20% to about 75% of the surface area of the substrate. Methods for forming such articles are also provided.