Magnesium Diaphragm Anodic Oxide Coating Weight Reduction
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Solution Overview
Problem
Magnesium diaphragms used in speakers are often heavy and thick due to existing rust-preventive and decorative coatings, which impairs their performance and sensitivity.
Innovation Solution
A magnesium diaphragm with a thin anodic oxide coating dyed with a dye is formed on a thin magnesium plate, combined with an electrodeposition coating, to provide anti-corrosiveness and decorative value while maintaining a lightweight structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick electrodeposition coating is applied for decoration after anodic oxidation, then the decorative value and anti-corrosiveness are enhanced, but the diaphragm becomes heavy and its characteristics are impaired
Solution Approach 1:
The patent changes the thickness parameter of the coating layer, specifying it to be 0.01 mm to 0.05 mm (10-50 μm). This optimized thickness range provides sufficient anti-corrosiveness and decorative value while minimizing weight increase and maintaining diaphragm characteristics.
Solution Approach 2:
The patent creates a composite structure consisting of the magnesium diaphragm substrate combined with a thin anodic oxide coating and electrodeposition coating. This composite structure integrates the lightweight properties of magnesium with the protective and decorative properties of the coatings in an optimized balance.
2Shape
If a thick electrodeposition coating is applied for decoration, then the decorative value is enhanced, but the diaphragm becomes heavy and sensitivity is reduced
Solution Approach 1:
The patent optimizes the coating thickness parameter to 0.01 mm to 0.05 mm, which is sufficient to provide decorative value through color and surface finish while keeping the added weight minimal and the diaphragm sensitive.
3Reliability
If baking finish is used to form primer and top layers, then anti-corrosiveness and decorative value are enhanced, but the coating becomes thick and heavy
Solution Approach 1:
The patent changes the coating formation method from baking finish to anodic oxidation followed by electrodeposition, with controlled thickness of 0.01 mm to 0.05 mm. This provides equivalent or superior anti-corrosiveness and decorative value with reduced thickness.
Solution Approach 2:
The patent replaces the thermal-baking process with an electrochemical process (anodic oxidation and electrodeposition). This substitution allows for better thickness control and more efficient material deposition, achieving the desired protective and decorative functions with thinner coatings.
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 magnesium diaphragm that is both lightweight and high in sensitivity, with improved anti-corrosiveness and decorative value, suitable for use in speaker applications without compromising sound quality.
Implementation Method 1
performing anodic oxidation on a substrate made by a thin magnesium plate bent in a predetermined shape to form an anodic oxide coating on a surface
Implementation Method 2
paint composed of a solvent and organic pigment is applied, thereby electrically depositing a color coating on the anodic oxide coating
Data Source
AI summary
A substrate (580) made by a thin magnesium plate having a thickness of at most 60 μm and bent in a predetermined shape is subjected to anodic oxidation using an alkali-mixture aqueous solution containing metallic salt with a pH 12 or more so that porous anodic oxide coatings (571) are formed on the surfaces thereof. A first treated substrate (581) having the anodic oxide coatings (571) is immersed in a bath of a dye (571B), which fills the pores (571A) of the anodic oxide coatings (571) and dyes the substrate, providing a second treated substrate (582). The second treated substrate (582) is subjected to electrodeposition using electrodeposition paint made mainly of acrylic resin, forming electrodeposition coatings (572) on the anodic oxide coatings (571). A magnesium diaphragm is thereby produced, which is thin and has sufficient sensitivity and desired characteristics. The diaphragm thus dyed has metallic gloss and hence acquires a high decorative value.