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Pure Copper

Pure copper offers the highest available thermal and electrical conductivity in additive manufacturing, ideal for energy-efficient, high-frequency, and heat-critical systems.

Introduction to Pure Copper for 3D Printing

Pure copper (≥99.95% Cu) provides unmatched thermal conductivity (~390–400 W/m·K) and electrical conductivity (>100% IACS), making it indispensable in RF shielding, heat exchangers, busbars, and electrical contacts. However, its high reflectivity and thermal conductivity require advanced additive manufacturing techniques.

Direct Metal Laser Sintering (DMLS) and Electron Beam Melting (EBM) enable precise geometries and conductivity retention when processed in controlled inert or vacuum environments.

International Equivalent Grades of Pure Copper

Country	Grade Number	Other Names/Titles
USA	C11000/C10200	ETP Copper / OFE Copper
Europe	CW009A	EN 13601
Japan	C1100/C1020	JIS H3100
China	T1/TU1	GB/T 5231

Comprehensive Properties of Pure Copper

Property Category	Property	Value
Physical	Density	8.94 g/cm³
	Melting Point	1,083°C
	Thermal Conductivity	390–400 W/m·K
	Electrical Conductivity	≥100% IACS
Chemical	Copper (Cu)	≥99.95%
	Oxygen (O₂)	≤0.001% (for OFE)
Mechanical	Tensile Strength	200–250 MPa
	Yield Strength	50–70 MPa
	Elongation	≥35%
	Hardness (Vickers HV)	~45–55 HV

Suitable 3D Printing Processes for Pure Copper

Process	Typical Density Achieved	Surface Roughness (Ra)	Dimensional Accuracy	Application Highlights
DMLS (Green Laser)	≥98%	8–12 µm	±0.1 mm	High-resolution features for electrical and thermal transfer parts
EBM	≥99.5%	20–30 µm	±0.15 mm	Best for large conductive parts requiring low oxide levels

Selection Criteria for Pure Copper 3D Printing Processes

Conductivity Prioritization: Green laser DMLS achieves >95% IACS; EBM retains full conductivity in large parts due to vacuum processing.
Application Type: Use DMLS for small, detailed electrical contact parts; use EBM for mass thermal systems like cold plates and busbars.
Oxidation Control: Argon (DMLS) or vacuum (EBM) atmospheres are critical to avoid conductivity-degrading oxide layers.
Post-Processing Compatibility: Pure copper is soft and easily machinable. CNC finishing is recommended for sealing surfaces and dimensional control.

Essential Post-Processing Methods for Pure Copper 3D Printed Parts

CNC Machining: Ensures ±0.02 mm tolerance and prepares surfaces for optimal electrical contact and heat transfer interfaces.
Electropolishing: Reduces surface roughness to <0.5 µm Ra, enhancing both conductivity and fatigue resistance for RF or power devices.
Thermal Annealing: Performed at 400–600°C to eliminate residual stress, restore ductility, and improve electrical uniformity.
Tumbling: Used for external surfaces with complex shapes to improve appearance and prepare for coatings or contact finishes.

Challenges and Solutions in Pure Copper 3D Printing

Laser Reflectivity: Specialized green lasers (515–532 nm) are used to maximize energy absorption in DMLS and ensure full melting.
Heat Dissipation During Printing: High thermal conductivity causes premature solidification; tightly controlled layer strategies prevent incomplete fusion.
Oxidation Sensitivity: Printing in environments with <10 ppm oxygen is mandatory to preserve high conductivity and mechanical integrity.

Applications and Industry Case Studies

Pure Copper is widely used in:

Electronics: RF cavities, shielding, connector pins, and signal distribution components.
Power Systems: Busbars, terminal blocks, and high-current carriers.
Thermal Management: Cold plates, heat exchangers, and LED cooling structures.
Aerospace & Defense: Passive thermal control structures, antenna elements, and propulsion interfaces.

Case Study: A 3D printed RF cavity in pure copper achieved >99% IACS conductivity and dimensional accuracy of ±0.08 mm after post-machining and electropolishing, enabling aerospace-grade performance.