Cut-Off and Grooving for Different Materials

 

When it comes to cut-off and grooving operations, material properties greatly influence tool selection, insert geometry, and machining strategy. This article outlines recommended approaches for machining various materials, including non-ferrous metals, high-temperature alloys, titanium alloys, and hardened parts.

 

I Cut-Off and Grooving of Aluminum and Non-Ferrous Metals

 

▲ Figure 1 Cut-Off and Grooving of Aluminum

 

Non-ferrous metals, such as aluminum, copper, and brass, are relatively soft materials. However, certain aluminum alloys-especially those with high silicon (Si) content, like 13% Si-can be extremely abrasive. For such materials, inserts with sharp cutting edges are essential to achieve high cutting speeds and long tool life.

 

To obtain these sharp cutting edges, similar to the RO-style geometry, ground insert edges are typically required. The recommended grade is uncoated or lightly coated carbide to reduce friction and wear. For parts requiring superior surface quality, polycrystalline diamond (PCD) tipped inserts are highly recommended. These tools enable high-speed machining with excellent tool life and fine finishes.

 

 

II Cut-Off and Grooving of Heat-Resistant Super Alloys (HRSA)

 

▲ Figure 2 Cut-Off and Grooving of HRSA

 

HRSAs are typically divided into three groups: nickel-based, iron-based, and cobalt-based alloys. Each group has distinct physical properties and machining behavior. Heat treatments such as annealing or aging significantly affect machinability, with material hardness varying between 150 and 440 HB depending on the treatment process.

 

In general, HRSAs are more difficult to machine than conventional steels and stainless steels. For optimal performance, the recommended insert geometries are -GF and -TF types. When high cutting speeds are desired, ceramic inserts can significantly improve productivity, thanks to their high-temperature resistance and wear performance.

 

 

III Cut-Off and Grooving of Titanium Alloys

 

▲ Figure 3 Cut-Off and Grooving of Titanium Alloys

 

Titanium alloys are often machined after annealing or solution and aging treatment, resulting in hardness values between 250 and 440 HB. These materials are even more challenging to machine than conventional steels or stainless steels, placing higher demands on cutting tools.

 

It is advisable to use uncoated carbide inserts with sharp cutting edges, such as those with a -GF geometry. Due to titanium's tendency to form long, continuous chips, effective chip control is crucial. To ensure efficient chip breaking and extend tool life, the use of high-pressure coolant systems on the machine is strongly recommended.

 

 

IV Hard Part Machining

 

▲ Figure 4 Hard Part Machining

 

Modern manufacturing increasingly requires complete machining in a single setup, leading to a growing demand for hard part turning. In such applications, cutting tool materials like cubic boron nitride (CBN) significantly boost productivity by replacing traditional grinding.

 

CBN tools can machine both through-hardened and induction-hardened parts with hardness levels ranging from 50 to 65 HRc. For grooving operations, -S geometry inserts are recommended, while -RE geometry inserts are suitable for profiling. For small bores, CBN-tipped grooving inserts are ideal. These tools are designed for both continuous and interrupted cutting, offering excellent surface finish and tight dimensional accuracy.