Here are a few typical materials for medical products and how to use a large-capacity grinding and polishing system to prepare them.
Titanium alloys: Due to the presence of surface deformation layers, it is a common problem that these alloys are difficult to prepare for slicing. This is due to the high sensitivity of the alloy to high temperatures, when the coolant is not properly aligned with the workpiece, or suddenly during processing. Perform cold working.
Titanium is a well-known implant material in a variety of implants, but each material has its own unique characteristics, and we will choose the most suitable one according to the desired characteristics.
Polishing with a finer diamond results in a larger, hard-to-remove deformation of the titanium sample. Chemical mechanical polishing using an oxidative polishing suspension to effectively remove residual deformation.
Nitinol: This is a material for endovascular stents. Nitinol is superelastic and is very suitable for stent applications due to its microstructure transformation and internal variation with internal changes.
The stent helps keep the coronary artery clear and reduces the chance of a heart attack. The stent is inserted into the blocked artery with a balloon catheter. The balloon is inflated and the stent is inflated and fixed. This keeps the arteries open and allows blood to flow more freely.
The structure observed before implantation was austenite. When compressed and mounted on the conduit, the structure undergoes martensite changes. Once implanted in the body, the stent expands to form a reverse martensite that transforms from martensite to austenite. This advantage is often referred to as bias stiffness.
There are automatic or semi-automatic grinding machines that reduce labor and improve the quality of the ground samples. Manual grinding requires employees to perform more complex tasks that may reduce productivity.
Stainless steel: Because stainless steel such as AISI 316L has the advantages of low cost, good mechanical properties and easy processing, manufacturers usually use these stainless steels in orthopedics. However, stainless steel alloys can present some challenges, such as incompatibility with surrounding bone tissue (due to higher density) and the possibility of alloy corrosion in body fluids. This is a major concern because the effects of corrosion by-products on human tissue can pose serious health risks.
For example, nickel ions are considered to be allergens that cause inflammation; they can cause carcinogenicity in the body, so low-nickel or nickel-free steels are developed. However, stainless steel is still commonly used in surgical implants and instruments. They can be used in stents, fracture fixation plates. And screws, spinal implant devices and aneurysm clips are found, to name a few. The reason for long-term use is surface modification to significantly improve surface passivation and increase the surface chromium concentration by electropolishing to obtain better passivation performance.
Cobalt-based alloy: Cobalt alloy is a structurally tough material with excellent wear resistance, corrosion resistance and good biocompatibility. Compared with iron-based or titanium-based medical alloys, their traditional processing technology is more expensive to manufacture. High, so it is more popular with medical applications. They are commonly found as artificial hip and knee joints, but are also used in acetabular cups and tibial trays.
