Solving stress damage in oriented silicon steel: Chemical milling process reshapes the manufacturing of high-efficiency motor cores

Industry Pain Points: The Invisible Cost of Stamping

In high-efficiency motor development, traditional stamping methods are increasingly becoming the bottleneck—particularly for next-generation electric drives and high-frequency systems.

• Grain boundary deformation caused by mechanical stress leads to magnetic domain distortion, directly raising core losses—especially under medium-to-high frequency operation (400Hz+).
• Burr formation results in short circuits between laminations, increasing eddy current loss, heat generation, and reducing motor efficiency and service life.
• Tooling constraints restrict magnetic circuit topologies—limiting innovation in flux path optimization (e.g., Halbach arrays, asymmetric pole arcs).

At a time when IE5+ efficiency standards and miniaturization dominate design goals, stamping-induced damage is no longer acceptable.

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The Game-Changer: Chemical Milling + High-Grade Silicon Steel

Chemical milling, when applied to oriented silicon steel, eliminates mechanical defects and enables cutting-edge motor designs.

 Think of it as a shift from brute-force forming to precision-controlled material science.

Formula for breakthrough performance:

 Chemical Milling + Premium Oriented Silicon Steel = Revolutionary Core Efficiency

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Three Technical Advantages that Matter (with Data)

Advantage	Technical Mechanism	Customer Benefit
Ultra-Low Core Loss	Non-contact etching preserves magnetic grain orientation; no plastic deformation	>30% reduction in core loss vs. stamping. Enables motors to hit IE5 efficiency.
Minimal Eddy Loss	Burr-free edges (≤0.01 mm), improved interlaminar resistance, zero shorting risk	Motor temperature drops by 15–25°C. Lifetime doubles due to reduced thermal stress.
Design Freedom	Photomask etching enables complex flux topologies (Halbach, skewed teeth, etc.)	Torque ripple ↓ 40%, acoustic noise < 45 dB (vs. 55–65 dB for stamped cores).

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High-Value Applications (Where This Tech Wins)

• EV Traction Motors
  Demand: >96% efficiency, lightweight, thermally stable
  → Chemical milling enables high-slot-fill, high-speed operation with minimal loss.
• Robotic Servo Motors
  Pain Point: torque ripple affects precision
  → Custom magnetic paths reduce pulsation and improve stability.
• Inverter Compressors for Appliances
  Requirement: UL compliance, noise < 50 dB
  → Burr-free, low-loss cores meet regulatory and performance specs.
• Aerospace Actuation Systems
  Challenge: weight and heat limits
  → Chemical-milled laminations reduce weight by >30%, maintain <70°C temp rise.

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Deep Dive: Engineering Advantages of Chemical Milling

Material Selection

• Recommended Grades:
  • JNEX series (Nippon Steel)
  • 20SQGD070 (Baosteel)
• Optimal Thickness:
  • 0.1–0.2 mm for high-frequency response

Process Control Highlights (Python-style visualization)

# Key Etching Parameters
etchant = "FeCl₃/HNO₃ blend"  # Ensures >89° sidewall angles
temp_control = "45±0.5°C"     # Prevents over-etching
mask_tolerance = "±5μm"        # Critical for magnetic symmetry

Performance Benchmark (400Hz Test Environment)

Metric	Stamped Lamination	Chemically Milled Lamination	Improvement
Core Loss (W/kg)	1.30	0.80	↓ 38.5%
No-Load Current	2.8 A	2.1 A	↓ 25%

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Why It Makes Business Sense

Capability	Value Delivered
Full-Stack Manufacturing	Slitting → Coating → Exposure → Etching → Annealing → Insulation
Material Efficiency	>95% utilization vs. 70–80% for stamping
Standards Compliance	Meets IEC 60404-8-4 (magnetic steel lamination specification)
Fatigue-Free Lifecycle	Thermal, mechanical, and magnetic reliability over 10+ years

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Strategic Outreach & Market Messaging

• Engineering Channel:
  Publish white paper: “Chemical Milling’s Role in Suppressing Torque Harmonics in Motors”
  Showcase loss comparisons at IEEE-ECCE conference
• Procurement / Management:
  Launch TCO calculator that shows 3–5 year ROI from energy savings
• Industry Media Campaign:
  Case Study Headline: “Leading EV OEM Achieves 97.2% Efficiency with Chemically Milled Cores”

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Summary: Performance Gains That Speak for Themselves

 30%+ lower iron loss
 Torque ripple cut nearly in half
 Motor heat reduced by 20+°C
 Noise dropped to <45 dB
 Supports non-traditional, performance-optimized magnetic layouts

“By eliminating stamping stress and burrs, chemical milling unlocks the full magnetic potential of silicon steel—delivering a leap in motor efficiency and performance.”