Stellram's five new NL turning grades benefit from CVD coatings that are tailored to the material being worked.
Multiple layers, 20 to 25 microns thick, are deposited on the substrate, using an advanced CVD coating process developed by Stellram, which ensures that the combination does not chip or flake.
The five NL turning grade inserts, NL200, NL250, NL300, NL400 and NL920, have four or five layers.
These coating layers are a TiN adhesion and finishing layer, a medium-temperature TiCN layer for wear resistance at high temperatures, a hard alpha-A12O3 layer with a thermal barrier to resist wear at high surface speeds, a TiN/ medium temperature TiCN/TiN layer for adhesion and wear resistance and a high temperature TiCN/TiN layer for adhesion and wear resistance at low to medium surface speeds.
In turning, the effect of the coatings is to ensure the tool flows into the workpiece, making it softer and easier to cut by reducing static and kinetic friction. A post-coating surface treatment gives a final finish to the insert; also improving friction resistance, while relieving stress within it.
The NL turning grades are featured in the company's latest Turning catalogue.