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Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450: A Technical Guide

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Introduction

Initially developed for application as an aerospace alloy because of its relative ease of formability, high strength, and ductility at temperatures up to 427°C (801°F), Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450 is an ideal candidate for rivets that secure aluminum aircraft panels, particularly in areas exposed to high engine exhaust temperatures.

Low Elastic Modulus

This alloy has been used as welded flange components that secure high-energy physics RF linear accelerator cavities (made from high-purity niobium), and has been drawn into superconductivity wire. It is used as a medical device material for cochlear hearing implants, and its low elastic modulus makes it a consideration for various medical and dental devices.

Machinability

Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450 is easily fabricated into structures and components. Although it is considered a refractory metal, processing techniques are the same as those for other titanium alloys. Parts are typically welded using the GTAW process but require the addition of trailing and backing shields. Due to its simple metallurgical structure, there is no requirement for post-weld heat treatment. Machining requires the use of solid fixture setups and high torque at low RPM ridge machine tools with sharp high rake cutters.

High Formability

With a minimal bend radius capability (down to a bend radius of 1t where t=sheet thickness) and low modulus of elasticity, Ti-45Nb Alloy is highly formable yet retains excellent tensile and elongation properties. It can also be cast into shapes with the same processes used to cast CP titanium.

Surface Oxidation Treatment

Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450 readily accepts surface oxidation treatment to enhance its hardness and wear resistance. “Nobelizing” is a common commercially available process to apply this type of surface treatment.

Corrosion Resistance Higher Ignition Resistance

Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450 provides improved corrosion resistance along with higher strength compared to that of Ti-7, 12, 16, and 26 in many chemical environments. Ti-45Nb Alloy has also proven to be a great success in the autoclave processing of gold ore. For many years gas vents, oxygen lances, steam spargers, valves and other pressure oxidation reactor components have been produced, put into service, and survived hot, concentrated sulfuric or hydrochloric acid. In addition, the metal has been shown to have higher ignition resistance when compared to CP Ti, thereby allowing further process optimization.

Another chemical processing application for Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450 is the oxygen-based, low-pressure, wet oxidation process for the treatment of wastewater and sludge. Because of its corrosion and higher ignition resistance, this material is an ideal candidate for the 200°C (392°F), 20 bar pressure with oxygen environment. The superior corrosion resistance of Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450 makes it well suited for service in various environments, including most organic and mineral acids below 150°C (302°F). Because of its stable oxide film, Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450 has excellent resistance to oxidizing acids, including mixtures of HNO3 and HCL; however, it is susceptible to attack from HF and other fluoride ions.

Acids and corrosive solutions that Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450 has shown good chemical resistance to include:
Hydrochloric (HCL)
Sulfuric (H2SO4)
Hydrobromic (HBr)
Hydroiodic (HI)
Saltwater / Brine / Salt Solutions

Potential Applications

Aerospace rivet material
High pressure oxygenated gas vents
Oxygen lances for pressure oxidation reactors
Valves for corrosive oxygenated processes
Chemical corrosion resistance
Medical implant devices
High energy physics and superconducting wire

Figure 1. Ferrallum 255 super duplex stainless (top coupon) showed extensive corrosion (50% of wall thickness) after eight months in a mining autoclave. Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450 (bottom coupon) showed no measurable corrosion after four months and has tested well for nearly two years.

Ferrellum 255 SDSS vs. Ti-45Nb

Specifications & Certificates

Plate, sheet, tube, pipe, bar, billet, extrusions, wire, castings.

Product Forms

ASTM
B265 – Titanium and Titanium Alloy Strip, Sheet and Plate
B338 – Seamless and Welded Titanium and Titanium Alloy Tubes
B348 – Titanium and Titanium Alloy Bars and Billets
B381 – Titanium and Titanium Alloy Forgings
B363 – Seamless and Welded Unalloyed Titanium and Titanium Alloy Welding Fittings
B861 – Titanium and Titanium Alloy Seamless pipe
B862 – Titanium and Titanium Alloy Welded Pipe
B863 – Titanium and Titanium Alloy Wire

AWS
AWS A5.16/A5.16M:2007 – Specification for Titanium and Titanium-Alloy Welding Electrodes and Rods. Ti Grade 36 weld wire is designated in AWS A5.16/A5.16M as ERTi-36.
AWS G2.4/G2.4M:2007 – Guide for the Fusion Welding of Titanium and Titanium Alloys

Chemical Composition

Nominal 55 wt% Titanium, 45 wt% Niobium

Ingot Chemistry Nb O C N H Fe Ti
Typical +/- 1.5% 850 175 75 5 250 +/- 1.5%
Specification 42.0-47.0 < 1600 < 400 < 200 < 35 < 300 Balance

Note: Interstitials are in units of ppm. To obtain units of wt%, divide by 10,000.

Physical Properties

Property Value
Density 5.7 g/cm³ (0.206 lb/cu.in)
Melting Point 1900°C (3452°F)
Phase Transition or Beta Transus No beta transus. Alloy is beta phase to room temperature.
Coefficient of Thermal Expansion (CTE) 9.03 x 10^-6/°C (5.02 x 10^-6/°F)
Thermal Conductivity 10 W/m·K (5.78 BTU/hr·ft·°F)
Specific Heat 0.427 J/g·°C (0.102 BTU/lb·°F)
Thermal Diffusivity 4.3 x 10^-6 m²/s (46.3 ft²/sec)

Mechanical Properties

Property Value
Ultimate Tensile Strength (at RT) 450 MPa (65,000 psi)
Yield Strength (at RT) Minimum 410 MPa (60,000 psi), Maximum 655 MPa (95,000 psi)
Elongation (at RT) 10% (in 2 inches)
High Temperature Strength Graphs See Figure 2 and Table 4
Bend Radius Under 0.070 inch (1.8 mm) thickness = 4.5T<br>0.070 to 0.187 inch (1.8-4.75 mm) thickness = 5T
Modulus of Elasticity 62.05 GPa (9 x10^6 psi)

Tensile StrengthTable 4. Mechanical Properties for Titanium Grade 2 and Niobium vs. Ti-45 Niobium

Material Elastic Modulus (psi) Yield Strength (psi) Ultimate Strength (psi) Integrated Thermal Contraction 293K to 1.88K (in/in)
Niobium 1.52E+07 55000 46000 0.0014
Ti-45 Niobium 9.00E+06 69000 79000 0.0019
Titanium Grade 2 1.55E+07 40000 50000 0.0015

Other Properties and Pertinent Information

Ti Ignition Curve

Ti-45Nb, Grade 36, 55Ti-45Nb, UNS R58450, provides a unique solution for demanding applications requiring both high performance and biocompatibility. Its advantages are clear, from medical implants to high-stress aerospace parts. By understanding its properties and choosing it wisely for the right applications, you can harness the potential of Ti-45Nb to improve outcomes, extend product life, and contribute to advancements in multiple industries.

ASTM B655/B655M Niobium-Hafnium Alloy Bar and Wire

Knowledge of ASTM B655 C-103 89Nb-10Hf-1Ti Alloy Bar and Wire

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Introduction

ASTM B655/B655M is a standard specification for C-103 (UNS R04295), an alloy composed primarily of niobium, hafnium, and titanium. This unique combination of metals results in a highly valued material for its exceptional properties, making it a critical component in various high-performance applications. This blog delves into the characteristics, advantages, and applications of ASTM B655/B655M C-103 (89Nb-10Hf-1Ti) Niobium-Hafnium Alloy Bar and Wire.

Composition and Properties

Composition:
Niobium (Nb): The primary element in the alloy, niobium provides a high melting point and excellent thermal conductivity.
Hafnium (Hf): Approximately 10% of the alloy, hafnium enhances the alloy’s strength and oxidation resistance.
Titanium (Ti): Around 1% of the composition, titanium improves the alloy’s overall mechanical properties and corrosion resistance.

Properties:
High Melting Point: C-103’s melting point is approximately 4310°F (2377°C), making it suitable for extreme-temperature applications.
Excellent Oxidation Resistance: The presence of hafnium significantly enhances the alloy’s ability to resist oxidation at high temperatures.
Superior Strength: The alloy maintains strength even at elevated temperatures, ensuring reliability and durability in demanding environments.
Corrosion Resistance: The addition of titanium contributes to the alloy’s resistance to various forms of corrosion, extending its service life.

Applications of C-103 Alloy Bar and Wire

Aerospace and Defense:
Rocket and Missile Components: Due to its high melting point and strength, C-103 is used to construct rocket nozzles, combustion chambers, and other critical components.
Turbine Engines: The alloy’s ability to withstand high temperatures and oxidation makes it ideal for turbine blades and engine parts.
Nuclear Industry:
Reactor Components: C-103’s resistance to radiation damage and high temperatures makes it suitable for various nuclear reactor components, including fuel cladding and control rods.
Medical Devices:
Implants and Surgical Instruments: The biocompatibility and corrosion resistance of C-103 alloy bar and wire make it an excellent choice for specific medical applications, such as surgical instruments and implants.
Industrial Applications:
Chemical Processing Equipment: The alloy’s corrosion resistance is beneficial in manufacturing equipment used in chemical processing industries.

Manufacturing and Processing

The production of ASTM B655/B655M C-103 alloy bars and wires involves precise metallurgical processes to ensure the highest quality and performance:
Melting and Alloying: The primary elements are melted together in a vacuum or inert atmosphere to prevent contamination and ensure a homogeneous alloy.
Forming and Shaping: The molten alloy is cast into billets or ingots, then hot worked into bars or wires through processes such as forging, rolling, and drawing.
Heat Treatment: The alloy undergoes heat treatment to achieve the desired mechanical properties and microstructure.
Quality Control: Rigorous testing and inspection ensure the alloy meets the required specifications and standards.

Benefits of Using C-103 Alloy

Enhanced Performance: The superior mechanical properties and high-temperature capabilities of C-103 alloy improve component performance and reliability.
Longevity: The alloy’s excellent oxidation and corrosion resistance contribute to longer service life and reduced maintenance costs.
Versatility: The alloy’s unique properties suit various industry applications.

Conclusion

ASTM B655/B655M C-103 (89Nb-10Hf-1Ti) Niobium-Hafnium Alloy Bar and Wire represents a pinnacle of metallurgical engineering, offering unparalleled performance in some of the most demanding environments. This alloy’s exceptional properties make it invaluable for high-performance applications, whether in the aerospace, nuclear, medical, or industrial sectors. By understanding the composition, properties, and applications of C-103 alloy, industries can make informed decisions to leverage its benefits for their specific needs. We provide expert guidance and high-quality products tailored to your specifications. Feel free to contact us at [email protected] for more information on how C-103 alloy can meet your high-performance material requirements.