How BioDur® 108 Stainless Steel Ensures Integrity and Cleanliness for the Medical Industry

For decades, stainless steel has been the go-to material for medical device instrumentation and implants due to its reliable corrosion resistance and strength. However, with the ever-evolving medical field demanding stronger, more durable, and biocompatible materials, Carpenter Technology has innovated to meet these needs. BioDur® 108 is an austenitic stainless steel specifically designed to address these challenges and ensure the integrity and cleanliness of medical devices.

BioDur® 108 is an essentially nickel-free, high-nitrogen austenitic stainless steel. Its unique composition offers several advantages over traditional nickel-containing alloys like 316L (ASTM F138), 22Cr-13Ni-5Mn (ASTM F1314), and 734 (ASTM F1586). Let's delve deeper into the properties of BioDur® 108 and how the Electro-Slag Remelting process refines it for medical applications.

The Electro-Slag Remelting (ESR) Process

The Electro-Slag Remelting (ESR) process is an advanced metallurgical technique used to refine metals like steel and superalloys. It significantly improves the material's purity, uniformity, and mechanical properties. Here's a breakdown of the ESR process:

1. A consumable electrode, made of the desired alloy, is submerged in a conductive slag layer within a water-cooled copper mold.

2. A high electrical current is passed through the electrode, generating intense heat that melts it.

3. The molten metal droplets fall through the slag bath, which refines them by removing impurities and protecting them from contamination.

4. The refined molten metal solidifies at the bottom of the mold, forming a new ingot with superior properties.

The ESR process is particularly valuable in the medical device industry because it ensures:

• Enhanced Cleanliness: By removing impurities, the ESR process minimizes the risk of corrosion and potential device failure within the body.

• Improved Microstructure: The process refines the grain structure of the metal, leading to increased strength and toughness.

• Exceptional Homogeneity: The uniform distribution of elements throughout the ingot ensures consistent material properties throughout the final medical device.

Characteristics of BioDur® 108 | Austenitic Stainless Steel

BioDur® 108 boasts several key characteristics that make it ideal for medical applications, with some limitations to consider:

• Nickel-Free: BioDur® 108's essentially nickel-free composition minimizes the risk of allergic reactions in patients with nickel sensitivities. This is a crucial factor for long-term implants and instrumentation that remain within the body.

• Cobalt-Free: Similar to nickel, cobalt can also trigger allergic reactions in some patients. BioDur® 108 being cobalt-free eliminates this concern, making it suitable for a broader range of patients.

• Superior Corrosion Resistance: Compared to 316L, BioDur® 108 offers superior resistance to pitting and crevice corrosion, which is essential for implants exposed to bodily fluids. Enhanced corrosion resistance helps to ensure the long-term integrity and functionality of medical devices within the body.

• High Strength: BioDur® 108 exhibits superior tensile and fatigue strength compared to nickel-containing alloys, which means implants and instruments can better withstand the stresses and strains experienced during surgery and throughout their life.

• Wear Resistance (Limitation): While BioDur® 108 offers many advantages, it's important to note that wear resistance is not a significant strength. Austenitic stainless steels, in general, are not work-hardened and don't exhibit exceptional wear properties. For applications requiring high wear resistance, Carpenter Technology offers alternative alloys specifically designed for those needs. 

Quality Specifications

BioDur® 108 meets stringent quality standards, including ISO 9001:2000 and AS9100, ensuring high-quality production processes and materials. It also conforms to medical industry standards such as ASTM F04 and ISO 5832, guaranteeing its suitability for medical applications. These certifications and standards ensure that BioDur® 108 maintains the highest level of performance, safety, and reliability for use in medical devices.

Medical Applications of BioDur® 108

BioDur® 108's unique properties make it a versatile material for various medical applications, including:

• Instrumentation and Surgical Tools: Instruments used in various surgical procedures can benefit from BioDur® 108's strength and cleanability. This stainless steel is resistant to corrosion and wear, ensuring the longevity and reliability of surgical tools even after repeated sterilization cycles. Examples include:

  • Bone drills

  • Clamps

  • High-precision forceps

  • Surgical staples

• Orthopedic: BioDur® 108's strength and biocompatibility make it ideal for orthopedic applications. It provides the necessary mechanical properties to support and repair the musculoskeletal system. Examples include:

  • Joint reconstruction components

  • Spinal fixation devices

  • Some trauma implants

  • Fracture fixation

  • Guide wires

  • Joint replacement

  • Spinal fixation

  • Artificial discs

  • Surgical instruments

  • Spinal motion preservation

• Dental: High-strength biocompatible materials resistant to corrosion and fracturing are essential for high-quality dental instruments. BioDur® 108 ensures durability and performance in the demanding environment of the oral cavity. Examples include:

  • Crowns

  • Fixation and orthodontia devices

  • Dental implants

  • Dental instruments

• Cardiology: BioDur® 108 is valuable in cardiology for its ability to maintain integrity and performance in critical applications. It supports the functionality and longevity of devices crucial for patient survival and health. Examples include:

  • Stents

  • Pacemaker components

  • Arterial plaque removers

  • Catheters

  • Chest closure wire

  • Hypodermic needles

  • Pacemakers and defibrillators

  • Surgical instruments

  • Surgical needles

  • Vascular repair (stents)

• General Surgery: BioDur® 108 is used in a variety of general surgery tools due to its strength and resistance to corrosion, making it suitable for repeated use in various surgical environments. Examples include:

  • Blades

  • Endoscopic/arthroscopic instruments

  • Hypodermic needles

  • Reamers

  • Staples

  • Surgical needles

  • Surgical instruments

  • Diagnostic equipment (MRI, X-ray)

  • Microsurgery tools

BioDur® 108 | Carpenter Technology

BioDur® 108 stainless steel represents a significant advancement in medical device materials. By combining its essentially nickel-free and cobalt-free composition with exceptional cleanliness achieved through ESR processing, BioDur® 108 offers many advantages for the medical industry.

As the medical field continues to push boundaries, BioDur® 108 stands as a testament to Carpenter Technology's commitment to developing innovative materials that enhance patient care and empower medical professionals.