Normally in finish hard turning chip control is not a problem, depth of cut is less than 0.5 mm, the hardness is over 550 HV1, and chips generated are brittle and will break without a chipbreaker.
If conventional PCBN inserts are used for machining into softer (< 50 HRC) material, long uncut chips can be a problem. In some processes, it is necessary to remove that case hardened layer, e.g. when preparing for welding. Chips can then become very long and stringy, and get entangled in the chuck, the component, the conveyor equipment etc, leading to problems and even causing the machine to be stopped for removing of the chips.
The main two application areas for PCBN chip breaker inserts are:
- Removing of case hardened layer on e.g. case hardened steel components
- Machining from hard to soft(er) material on e.g. induction hardened components
- Inner diameter machining with poor chip evacuation
The laser machined chip breaker comes in two different styles, one for low (non-wiper) and one for high (wiper) feed applications. The non-wiper chip breaker insert makes it possible to have good chip control when low feed rates are used. The wiper chip breaker insert provides improved chip control when using high feed rates.
Below is an enlargement of the “chip breaker geometry” (left), and close-ups of the chip formation without chip breaker (middle) and with chip breaker (right).
The addition of a chip breaker can substantially improve process reliability and productivity. The left example below is an example of removing the case hardened layer (preparing for welding). In the right example below, the customer had problems with chip evacuation, and had to stop the machine and manually remove chips from the component and tool holder. After introducing chip breaker inserts, they could run without stops. As an additional benefit, tool life was also increased.
For more information, please contact your local Seco representative, or our Advanced material (PCBN/PCD/CERAMIC) team.
Product Specialist SECOMAX PCBN/PCD/CERAMIC
SECO TOOLS Shanghai CO., Ltd. Level 2, Building 8, 456 HongCao Rd., Shanghai 200233, China
Office: +86 21 5426 5849
Mobile: +86 186 167 90063
Product Manager SECOMAX PCBN/PCD/CERAMIC
SECO TOOLS AB
737 82 Fagersta, Sweden