PVD electroplating is more expensive than water electroplating. Why do medical equipment manufacturers use PVD coating more and more?  Because PVD coating can provide more beautiful appearance and functional advantages.

As we all know, physical vapor deposition (PVD) is a vacuum coating process that was first used to improve the hardness, wear resistance, and service life of cutting tools.  The tool life with PVD coating is 10 times longer than the tool life without coating.

Because PVD coatings can provide better edge retention, prevent oxidation and corrosion, and remain clear during the cutting process, and will not react with bones, tissues or body fluids, more and more are used in medical devices, such as sharp  Surgical instruments, needles, drills, jammers, various device components, and “wear and tear” parts for dental applications.

How many PVD coatings are commonly used in medical devices?

There are four kinds.  The most commonly used is Titanium Nitride (TiN), the coating is golden, the thickness ranges from 0.0001 to 0.0002 inches, and the Vickers hardness ranges from 2,400 to 2,600HV.

Followed by aluminum titanium nitride (AlTiN), the coating is carbon black, the thickness ranges from 0.0001 to 0.0002 inches, and the hardness ranges from 4,000 to 4,200 HV.

The third is chromium nitride (CrN, silver plating, with a thickness ranging from 0.0001 to 0.0005 inches, and a hardness ranging from 2,200 to 2,400HV.

Alpha is a multilayer coating with zirconium nitride (ZrN) on the top layer and produces a silver-gold color.  Its thickness ranges from 0.0001 to 0.0002 inches, and its hardness is the highest at 4,400 to 4,600 HV.

Are all used in those medical materials?

Commonly used 303, 440C and 17-4 stainless steels, titanium alloys and some tool steels, but not suitable for aluminum, because the temperature of the PVD coating process (500°C) is close to the melting point of aluminum.

Will such a high temperature affect the material?

It may change the hardness of the material or cause deformation (shrinkage or growth) of the part. In order to minimize this possible influence, it is usually recommended to temper the heat-sensitive part at 580°C to 510°C before coating it.  .

What are the advantages of PVD over CVD process?

The process requires a lower temperature, no secondary heat treatment is required after coating, and the surface finish of the original material is maintained without re-polishing.

What are the advantages of PVD over anodizing?

More wear-resistant, the color stays longer, the simple one is better looking and more durable.