I. Manufacturing Process
The outer shell is a slender, thin-walled aluminum alloy cylindrical structure with a red anodized finish. Balancing lightweight design, aesthetic appeal, and assembly compatibility, the core process utilizes aluminum profile extrusion/stretching + CNC precision machining + surface treatment. The specific steps are as follows:
1. Raw Material Selection: 6063 aluminum alloy is used (good extrusion/stretching formability, excellent anodized color performance). For small-batch high-end models, 6061 aluminum alloy (higher structural strength) can be selected, using aluminum rods or tubes as raw materials.
2. Blank Forming:
◦ Cold Stretching: The aluminum tube blank is cold-stretched into a thin-walled cylindrical blank, ensuring uniform wall thickness (tolerance ≤ 0.1mm) to meet the lightweight requirements of e-cigarettes/power banks.
◦ Profile Extrusion: During mass production, custom molds are used to extrude irregularly shaped aluminum profiles, forming the basic outline of the shell in one piece, reducing subsequent processing steps.
3. CNC Precision Machining:
◦ Using CNC lathes and CNC machining centers, the end faces of the casing are precision turned, port slots are milled, and charging port/button holes are drilled and tapped. Micro-cutting processes are used on thin-walled areas to prevent deformation.
◦ Edges are chamfered and deburred (rounded corners R0.3~0.5mm) to improve grip.
4. Surface Treatment:
◦ Red Anodizing: The oxide layer thickness is controlled at 10~15μm. A uniform bright red effect is achieved through a color-matching process, while simultaneously improving corrosion resistance and wear resistance. The surface can be sandblasted to create a matte/semi-matte texture.
◦ High-Gloss Machining: If the casing requires localized high-gloss finishing, the designated areas are precision-machined to a high-gloss finish (roughness Ra below 0.2μm) before anodizing.
◦ Laser Marking: For mass-produced products, logos, parameters, and other information can be laser-engraved on the casing surface without damaging the oxide layer.
5. Inspection and Trial Assembly: Inspect the dimensional accuracy and wall thickness uniformity of the outer shell, and perform assembly and trial fitting with the internal battery and circuit board modules to verify the smoothness of insertion/removal/opening.
II. Machining Accuracy
This outer shell meets the miniaturization and precision requirements of 3C products. The core accuracy indicators are as follows:
1. Dimensional Accuracy:
◦ Outer diameter tolerance: ±0.05mm, inner diameter tolerance ±0.03mm, ensuring a tight fit with the internal modules.
◦ Port slot dimensional tolerance: ±0.02mm, ensuring a secure snap-fit connection with the cover.
◦ Hole position accuracy: ≤0.05mm, hole diameter tolerance H7 grade, suitable for the assembly of charging interfaces and buttons.
◦ Outer shell length tolerance: ±0.1mm, suitable for the overall size requirements of 3C products.
2. Geometric Tolerances:
◦ Outer shell cylindricity: ≤0.05mm/100mm, preventing bending of the shell from affecting assembly. ◦ Perpendicularity of end face to axis: ≤0.03mm, ensuring a tight fit between the cover and the casing.
◦ Wall thickness uniformity: Deviation ≤0.08mm, preventing deformation of thin-walled areas under stress.
3. Surface Precision:
◦ Anodized surface roughness Ra1.6~3.2μm, ensuring uniform color and smooth feel.
◦ High-gloss surface roughness Ra0.2~0.4μm, achieving a mirror-like decorative effect.
◦ Non-appearance surface roughness Ra6.3μm, meeting basic usage requirements.
III. Industry Applications
This type of aluminum alloy casing, due to its lightweight, corrosion resistance, and highly customizable appearance, is primarily used in the portable 3C product field, specifically in the following scenarios:
1. Electronic Cigarette/Atomizer Field:
◦ Refillable e-cigarette main unit casing and disposable atomizer casing, utilizing the texture of aluminum alloy to enhance product quality, while the thin-walled structure adapts to portability needs.
2. Power Banks/Energy Storage Products:
◦ Mini power bank casings, portable energy storage power bank cylindrical casings, made of aluminum alloy for both heat dissipation and structural protection.
3. Portable Digital Accessories:
◦ Portable solid-state drive (PSSD) casings, wireless charging receiver casings; lightweight design for easy carrying, anodized finish protects against scratches.
◦ Bluetooth headset charging case casing (cylindrical), balancing aesthetics and structural rigidity.
4. Wearable Device Accessories:
◦ Smart bracelet strap connector casings, smartwatch charging dock casings; miniaturized design adapts to the size requirements of wearable products.
