The Coating Process: CVD v PVD
So, you’ve decided that your shop could benefit from coated cutting tools, great! You’ve embarked along a valuable method of tool maintenance, one that will increase your productivity and reduce downtime.
Of the many points of conversation, you will need to have with your contractor, the way in which the tools are coated are just as important. And while the shop will most likely make the choice for you, it would be beneficial to know:
(1.) Which tool coating process you’d be looking for Chemical Vapor Deposition (CVD) or Physical Vapor Deposition (PVD). And (2.) which application or substrate the coating performs best with.
Understanding the characteristics associated with each process will not only speed up your ordering process but also allow you to make the best decision for your operations.
What are the characteristics of CVD?
●Processed in atmospheric or vacuum reactor
●1925-degree Fahrenheit standard temperature
●Virtually any surface can be coated
●Chemical and Metallurgical Bond
●Average thickness between .0002-.0005
●Limited range of material usage
●Loose Tolerance Range
●Steel requires heat treating
●Higher rate of edge build-up
●Requires post-coating finishing
What are the characteristics of PVD?
●Vacuum chamber processed
●320 to 900 Fahrenheit standard temperature
●“Line of sight” coating process
●Average thickness .00004 - .0002
●Wide range of material usage
●Recommended for tight tolerances
●No heat treatment required
●No excessive build-up
●Coating replicates finish
What application do CVD coatings best serve?
While many CVD coatings are used in manufacturing applications, CVDs are most commonly used in metal-forming tools. A looser tolerance and higher temperature will allow CVDs to perform better than their “colder” coated counterparts. The heat-induced chemical/metallurgical bonding in CVD processes creates adhesion bonds that are unmatchable to PVD.
What applications do PVD coatings best serve?
As indicated above where CVD has a stricter application list, PVD coatings are successful in a wide range of substrates and applications. Characteristics like lowered edge build-up, low range of processing temperature and application thickness make it ideal for HSS and carbide cutting tools.
Unless you’re running the same operation day in and day out, you’re going to need to reevaluate your project specifications. As these factors are integral to the success of your project. When you combine the understanding of coating tool processes and coating applications your coating needs should start to come into focus.
If you’re interested in learning more about coatings and how they can increase your productivity then let's get in touch! Contact us today.