Electrolytic polishing, stainless steel surface grades, and silicon carbide CNC machining methods and their industry applications.
1. Electropolishing (EP)
1️⃣ Process Principle
Electropolishing is an electrochemical surface treatment that removes material from a workpiece. The workpiece acts as the anode in an acidic electrolyte under controlled current:
- Surface peaks dissolve preferentially
- Achieves micro-level smoothing
- Removes deformed layers, burrs, and micro-particles
📌 Key Concept:
Not mechanical polishing, but controlled material dissolution
2️⃣ Relationship with CNC Machining
Typical issues after CNC machining:
- Tool marks
- Burrs
- Work hardened layer
- Particle contamination
👉 Electropolishing is a critical post-processing step after CNC machining
Especially suitable for:
- SUS304 / SUS316
- Complex internal geometries (holes, flow channels)
3️⃣ Industrial Applications
🔬 Semiconductor Equipment
- Ultra-clean requirements
- Particle contamination reduction
💊 Medical & Biotechnology
- Improved anti-bacterial performance
- Smooth, crevice-free surfaces
🧪 Food & Chemical Industry
- Easy cleaning (CIP / SIP)
- Residue prevention
4️⃣ Common Products
Semiconductor:
- Vacuum chambers (inner surfaces)
- Gas pipelines / valve bodies
- Wafer carriers
Medical:
- Surgical instruments
- Stainless steel tubing
Precision Equipment:
- Micro-channel components
- Nozzles
2. Stainless Steel Surface Finish Grades
1️⃣ Fundamental Concept
Surface finish is a combined result of material condition, machining, and surface treatment, not a single process.
Standards include: ASTM / JIS / EN
2️⃣ Common Grades (Relevant to CNC)
🔹 No.1 (Hot Rolled, Pickled)
- Rough surface, no polishing
- Used as raw material before CNC
Applications: structural and non-appearance parts
🔹 2B (Cold Rolled, Matte)
- Most common industrial grade
- Flat and clean surface
👉 Main material for CNC machining
🔹 BA (Bright Annealed)
- Bright, near mirror-like finish
Applications:
- Clean equipment
- Semiconductor / food-grade housings
🔹 HL (Hairline)
- Directional brushed finish
Applications:
- Equipment exterior
- Industrial design parts
🔹 #4 (Brushed Finish)
- Finer and more uniform than HL
🔹 Mirror Finish
- Surface roughness Ra < 0.1 μm
Typically combined with:
- Mechanical polishing + Electropolishing
3️⃣ Impact on CNC Machining
Surface grades affect:
- Tool selection
- Cutting parameters
- Post-processing methods
Examples:
- 2B → CNC → Electropolishing
- BA → Precision machining → Surface preservation
4️⃣ Industrial Applications
🔬 Semiconductor
- BA + EP (standard solution)
- Ultra-low roughness requirements
⚙️ Precision Equipment
- 2B / HL
🏗 Architecture / Exterior
- HL / #4 / Mirror
5️⃣ Common Products
- Semiconductor equipment housings
- Vacuum chambers
- Stainless steel frames
- Precision mechanical parts
- Panels / covers
3. Silicon Carbide (SiC)
1️⃣ Material Characteristics
SiC is a high-performance engineering ceramic with:
- Extremely high hardness (near diamond)
- High thermal conductivity
- Excellent thermal stability
- Superior corrosion and plasma resistance
2️⃣ CNC Machining Characteristics
👉 Reality: SiC is not suitable for conventional CNC cutting
Reasons:
- Extreme hardness → rapid tool wear
- Brittleness → risk of cracking
3️⃣ Actual Machining Methods
- Grinding (diamond wheel)
- EDM (for conductive SiC)
- Laser machining
- Ultrasonic machining
👉 CNC role:
- Pre-machining
- Positioning and assembly features
4️⃣ Industrial Applications
🔬 Semiconductor Industry (Major Market)
SiC is a core material for advanced semiconductor equipment
Applications:
- Plasma etching systems
- CVD equipment
- Wafer carriers
🚗 Electric Vehicles
- SiC wafers
- Power devices (MOSFETs)
🔥 High-Temperature Industry
- Furnace components
- Heat-resistant structures
5️⃣ Common Products
Semiconductor:
- Focus rings
- Shower heads
- Susceptors
- Edge rings
Advanced Components:
- Precision ceramic bases
- Plasma-resistant parts
🔶 Integrated Industry Perspective
Semiconductor Equipment Example
| Component | Material | Process |
|---|---|---|
| Chamber | SUS316L | CNC + Electropolishing |
| Housing | SUS304 HL | CNC |
| Core Zone | SiC | Precision ceramic processing |
👉 System Structure:
Metal structure + Surface treatment + Ceramic core
🔷 Summary (For Sales Use)
- Electropolishing = Surface quality & cleanliness enhancement
- Stainless steel grades = Base material & functional performance
- SiC = Core material for advanced processes
👉 Together supporting:
- Semiconductor industry
- Medical equipment
- High-end precision engineering
#Electropolishing
#CNCPrecisionMachining
#StainlessSteelSurfaceFinish
#SemiconductorEquipmentParts
#SiliconCarbideSiC
#UltraCleanProcessing
#VacuumChamber
#PrecisionEngineering
Yongyi Technology Co., Ltd.
location_on 42756 No. 188-9, Section 1, Dafeng Road, Tanzi District, Taichung City, Taiwan
email yongyi-sales@umail.hinet.net
email justinwu6767@gmail.com