Answers to Common Questions About CNC Machining in the Medical Industry

1.    What are the special requirements for materials commonly used in CNC machining of medical parts? 

    Materials used for medical parts must possess excellent   biocompatibility  ,   corrosion resistance  ,   non-toxicity  , and sufficient   mechanical strength  . This means they must not cause adverse reactions with human tissues, can operate stably in a bodily fluid environment for extended periods, and can withstand repeated sterilization and various stresses. Commonly used materials include   medical-grade stainless steel (316L)  ,   titanium alloys (TA1, Ti6Al4V)  ,   cobalt-chromium-molybdenum alloys  , and   PEEK (Polyetheretherketone)  .

2.    How can CNC process optimization reduce surface defects in medical parts? 

    The key to reducing surface defects lies in the refinement of process control. Beyond the previously mentioned tool and cutting parameter optimization, this also includes:

          Toolpath Planning:   Utilize optimized toolpaths such as contour-parallel and spiral milling to minimize tool retractions and re-engagements on the workpiece surface, thereby avoiding the creation of seam marks.

          Vibration Damping:   Ensure the rigidity of the machine tool, fixture, and tooling system to minimize vibrations during machining, as vibration is the primary cause of chatter marks and tool marks.

          Environmental Control:   Perform precision machining in a clean environment to prevent dust and impurities from contaminating the workpiece surface.

          Deburring Processes:   Employ advanced techniques such as electropolishing, tumbling, and high-pressure water deburring to thoroughly remove micro-burrs, avoiding secondary damage that might be introduced by manual deburring.

3.    What is the relationship between dimensional accuracy and surface roughness in medical parts? 

    Dimensional accuracy and surface roughness are two independent yet interrelated indicators of part quality. High dimensional accuracy is often a prerequisite for high surface roughness, but this is not absolute. For example, a part with extremely high dimensional accuracy may still have deep tool marks, resulting in poor surface roughness, and vice versa.

    In the machining of medical parts, both need to meet high standards. By selecting high-precision equipment, optimizing machining parameters, and implementing strict full-chain quality control, a synergistic improvement in both dimensional accuracy and surface roughness can be achieved. For instance, high-precision grinding can both improve dimensional accuracy and significantly reduce surface roughness.