Machining metal generates heat, and coatings are all about providing resistance to that heat while also providing some other tangible benefits as well. The make-up of the coating depends on the cutting application and the coating machine itself. Variables like work material, cutting fluid, cutting tool type and even part tolerances can all play roles in coating selection.
Cutting tool coatings are designed to improve wear properties via higher hardness, increased thermal stability and reduced coefficients of friction. In a new series of posts, we’ll review the different types of coatings we offer to make your cutting tools provide better performance. First up: AlTiN.
AlTiN. For when things heat up.
This chemical compound is named for the three elements that make up its composition: Aluminum, Titanium, and Nitride. It, along with most coatings we will discuss in this series, is applied to tools using the PVD (physical vapor deposition) method. While TiAIN is made up of the same basic components, the percentages of aluminum and titanium differ. Based upon the application, one may work slightly better than the other, but for our purposes here we will place them both in the same category.
Once deemed a new innovation, AlTiN is now considered a general purpose coating with high aluminum content. Applied to the tool with a coating thickness between 2-4 microns, it provides excellent heat and oxidation resistance. This is partly due to its nano hardness of 36 gpa (gigapascal – a unit of pressure). AlTiN remains stable at operating temperatures up to 1,292F°. Uncoated tools get into trouble at around 572°F.
One note about AlTiN is its application in wet machining environments (which, obviously, is most of them). Simply put, AlTiN performs best in applications where temperatures are both elevated and stable, as consistently high temperatures essentially activate the aluminum in the coating, improving performance. When run wet, temperatures fluctuate up and down, somewhat reducing the coating’s maximum performance capabilities.
What does all this mean for you? Higher feeds and speeds when machining ferrous materials, for starters. Better tool life, too. AlTiN is a good coating for dry machining and machining titanium alloys, Inconel, stainless alloys, and cast iron.
AlTiN coatings are available on the following GWS tool groups:
• 210 Series – 335 | 3FL | Radius
• 215 Series – 335BN | 3FL | Ball Nose
• 220 Series – 545 | 5FL | Square & Radius
• 240 Series – S94 | 2FL | Chamfer Mill
• 241 Series – S94 | 4FL | Chamfer Mill
• 243 Series – CM2 | 2FL | 90 deg. | Chamfer + End Mill
• 4005 Series – ECO | 2FL | 5xD | Solid | Inch & Metric
And of course, we can always add AlTiN to a custom tool designed specifically to your needs.
Contact us to see if AlTiN or any of our other coating options will help you achieve better results. But whatever you do, don’t run a bare tool. Put a coat on it!