1.Medical Stainless Steel
Medical stainless steel is one of the most widely used materials in the biomedical field. It is primarily employed in the replacement and repair of skeletal systems, as well as in dentistry, cardiac surgery, and the creation of cardiovascular stents. Among stainless steels, austenitic varieties, especially 304, 316, and 316L, offer superior corrosion resistance. Of these, 316L stainless steel is commonly used for medical implants, such as artificial joints (joint stems and heads), puncture needles, catheters, and needle tubes, due to its durability and biocompatibility.
2.Medical Cobalt-Based Alloys
Cobalt-based alloys are another essential material in healthcare, particularly for long-term implants subjected to severe in vivo loading conditions. While these alloys are often more suitable than stainless steel for such applications, their higher cost and potential biological issues—such as sensitization from the cobalt (Co) and nickel (Ni) elements—limit their widespread use. To address these concerns, recent advancements in surface modification technologies have significantly enhanced the surface properties of cobalt-based alloys, improving their clinical performance. The most common cobalt alloys are Co-Cr alloys, which include two main grades: Co-Cr-Mo and Co-Ni-Cr-Mo. The forged Co-Ni-Cr-Mo alloy, for example, is now used to manufacture the main stems of joint replacement prostheses, such as those for knee and hip replacements.
3.Medical Titanium and Titanium Alloys
Titanium and its alloys are widely used in clinical applications, including the manufacture of artificial joints, bone plates, and screws. These materials are commonly used for hip joints (including femoral heads), knee joints, elbow joints, metacarpophalangeal joints, interphalangeal joints, mandibles, artificial vertebral bodies (spinal orthoses), pacemaker casings, artificial hearts (including heart valves), dental implants, and titanium mesh for cranial reconstruction. One of the key advantages of titanium alloys is their elastic modulus and density, which are similar to those of human hard tissues, making them ideal for orthopedic applications. Among titanium alloys, Ti-6Al-4V is particularly notable for its superior performance and is widely used in the production of artificial joints and orthopedic internal fixation devices.
4.Nickel-Titanium Shape Memory Alloys
Nickel-titanium shape memory alloys (NiTi) have seen increasing use in medicine since their introduction, with applications extending beyond orthopedics and dentistry. In recent years, these alloys have gained popularity in cardiovascular treatments, particularly for stent interventions. NiTi stents are now commonly used in the treatment of coronary heart disease, offering enhanced flexibility and biocompatibility.
5.Other Medical Metals And Alloys
Other notable medical metals and alloys include magnesium alloys, platinum-group metals, and tantalum, each of which is used in specific applications due to their unique properties, such as biocompatibility and resistance to corrosion.
