Tantalum Coil Tube (Ta Coil Tube) — Technical Specification

1. Product Overview

The Tantalum Coil Tube (Ta Coil Tube), manufactured by Wenzhou Jixing Metal Materials Co., Ltd, is a precision-engineered continuous coil tube formed from high-purity tantalum metal or tantalum alloys. Unlike conventional carbon steel or stainless steel coil tubes, tantalum coil tubes are distinguished by their exceptional chemical inertness, outstanding corrosion resistance in aggressive media, and superior mechanical properties at elevated temperatures. The coil configuration enables efficient downstream processing, including cold drawing, heat treatment, and forming operations, while minimizing material waste and preserving the metallurgical integrity of the tantalum substrate.

This product falls within the category of specialty metallic coil tubes designed for demanding industrial applications where conventional materials fail due to corrosion, thermal degradation, or contamination concerns. The manufacturing process draws upon advanced powder metallurgy, vacuum melting, and precision forming technologies to achieve consistent dimensional accuracy and metallurgical quality.

2. Material & Properties

2.1 Base Material

The primary material used in the production of tantalum coil tubes is high-purity tantalum (Ta), with a minimum purity grade of 99.95% (RFA — Refined and Annealed). Alternative grades may include tantalum-tungsten alloys (Ta-2.5W, Ta-10W) for enhanced mechanical strength and reduced ductility at elevated temperatures, or tantalum-molybdenum alloys (Ta-10Mo) for improved formability.

2.2 Physical Properties

2.3 Mechanical Properties (Annealed Condition)

2.4 Chemical Properties

2.5 Unique Selling Points

3. Specifications

Parameter Specification Standard / Reference
Outer Diameter (OD) 3.0 – 25.0 mm (custom ranges available upon request) ASTM B298 / GB/T 20401
Wall Thickness 0.3 – 3.0 mm ASTM B298
Coil Length (Coil Length) 5 – 50 m per coil (continuous) Manufacturer specification
Coil Inner Diameter (Coil ID) 50 – 200 mm (reel diameter) Manufacturer specification
Surface Finish Machined / Ground / Polished (Ra ≤ 0.8 μm available) ISO 1302
Material Grade 99.95% Ta / Ta-2.5W / Ta-10W / Ta-10Mo ASTM B298 / GB/T 20401
Delivery Condition Annealed (Annealed) / Solution Treated —
Dimensional Tolerance (OD) ±0.05 mm (±0.002 in) ISO 4949
Dimensional Tolerance (Wall) ±0.03 mm (±0.001 in) ISO 4949
Roundness Tolerance ≤ 5% of wall thickness ISO 4949
Straightness ≤ 1.5 mm/m Manufacturer specification
Coil Winding Tolerance ±0.5 mm per layer Manufacturer specification
Maximum Operating Temperature 1,500 °C (vacuum/inert); 500 °C (oxidizing atmosphere) Material datasheet
Standard Lengths (Cut) 1 m, 2 m, 3 m, 5 m, 10 m (upon request) —

4. Manufacturing Process

The production of tantalum coil tubes involves a multi-stage manufacturing sequence that integrates powder metallurgy, vacuum consolidation, thermomechanical processing, and precision finishing. Each stage is critical to achieving the required metallurgical quality, dimensional accuracy, and surface integrity.

4.1 Raw Material Preparation (Raw Material Preparation)

  1. Reduction of Tantalum Pentoxide (Reduction of Tantalum Pentoxide): Tantalum oxide (Ta₂O₅) is reduced to metallic tantalum powder using sodium or hydrogen reduction methods, achieving a purity of ≥99.95%.
  2. Powder Purification (Powder Purification): The resulting tantalum powder undergoes vacuum distillation or zone refining to eliminate residual impurities (Fe, W, Mo, C, N, O, H).
  3. Particle Size Control (Particle Size Control): Powder particle size is controlled to 5–50 μm to ensure uniform consolidation and homogeneity in the final product.

4.2 Consolidation (Consolidation)

  1. Hot Isostatic Pressing (Hot Isostatic Pressing — HIP): Tantalum powder is compacted under high gas pressure (100–200 MPa) and elevated temperature (2,000–2,400 °C) in a vacuum or argon atmosphere. This process achieves near-full density (≥99.5% theoretical density) with minimal porosity.
  2. Vacuum Arc Melting (Vacuum Arc Melting — VAM): For alloy grades, tantalum is melted under high vacuum (≤10⁻³ Pa) using an electrode arc process, ensuring compositional homogeneity and absence of atmospheric contamination.
  3. Electroslag Remelting (Electroslag Remelting — ESR): An additional refining step that eliminates macrosegregation and inclusions, producing ingots with superior internal quality.

4.3 Homogenization Heat Treatment (Homogenization Heat Treatment)

The consolidated ingots or billets are subjected to homogenization at 2,200–2,500 °C for 2–8 hours under vacuum or inert gas atmosphere. This step dissolves any residual microstructural inhomogeneities and ensures uniform grain structure prior to thermomechanical processing.

4.4 Thermomechanical Processing (Thermomechanical Processing)

  1. Hot Forging / Hot Rolling (Hot Forging / Hot Rolling): Homogenized billets are hot forged or hot rolled at temperatures above 2,000 °C to reduce cross-sectional area and produce bar or strip stock suitable for tube formation.
  2. Intermediate Annealing (Intermediate Annealing): Periodic annealing at 1,200–1,500 °C under vacuum relieves accumulated deformation strain, restores ductility, and prevents cracking during subsequent forming operations.
  3. Cold Drawing (Cold Drawing): The hot-worked stock is cold drawn through precision tungsten carbide dies to achieve the final outer diameter and wall thickness specifications. Cold drawing induces controlled work hardening and improves dimensional accuracy.
  4. Final Annealing (Final Annealing): The drawn tube is annealed at 1,000–1,500 °C under high vacuum (≤10⁻⁵ Pa) to relieve residual stresses, restore full ductility, and achieve the desired grain structure (typically fine-grained, equiaxed morphology).

4.5 Precision Finishing (Precision Finishing)

  1. Surface Grinding / Polishing (Surface Grinding / Polishing): For applications requiring tight dimensional tolerances or superior surface finish, the tube undergoes precision grinding or electrochemical polishing to achieve Ra ≤ 0.8 μm.
  2. Chemical Cleaning (Chemical Cleaning): The tube is cleaned using a sequence of alkaline degreasing, acid pickling, and deionized water rinsing to remove surface contaminants and restore the passive oxide film.
  3. Non-Destructive Testing (Non-Destructive Testing — NDT): The tube is subjected to eddy current testing, ultrasonic inspection, and visual examination to detect internal and surface defects.

4.6 Coiling (Coiling)

The finished tube is wound onto precision-machined steel reels under controlled tension to prevent kinking, wrinkling, or plastic deformation. The coiling process is performed at room temperature in a controlled environment (temperature: 18–25 °C; relative humidity: ≤65%) to minimize oxidation and contamination.

5. Applications

5.1 Chemical Processing Industry (Chemical Processing Industry)

5.2 Semiconductor Manufacturing (Semiconductor Manufacturing)

5.3 Medical and Pharmaceutical (Medical and Pharmaceutical)

5.4 Aerospace and Defense (Aerospace and Defense)

5.5 Energy Sector (Energy Sector)

6. Quality Certifications and Standards

6.1 Applicable Standards

6.2 Quality Assurance System

6.3 Testing and Inspection