[] A new PCD cutter able to machine both aluminium and bi-metal (grey iron-aluminium) workpieces by utilising a number of indexable inserts, each optimised for different applications;
[] Two new long-life solid carbide cutters (MC319 and MC320 Advance) specifically for roughing;
[] An expanded range of M4000 cutters of up to 315 mm diameter for larger workpieces; and
[] The next generation Xtra·tec XT (Xtended Technology) shoulder and face mills for increased productivity and process reliability.
Of particular interest to automotive OEMs and top tier suppliers, the PCD cutter uses a variety of standard inserts in a single tool that is able to rough (up to 8 mm deep) and finish (0.5 to 0.8 mm) mill aluminium, and finish mill bi-metal workpieces. It reduces tooling costs by obviating the need for multiple tools for varying operations on different workpiece types.
While around 70% of modern engine blocks are of aluminium, bi-metal blocks usually have components like cylinder liners of grey cast iron inserted into the aluminium body. The machining process, especially roughing and finish milling, of such workpieces was previously only possible using a range of different tools – therefore increasing tool costs, as well as increasing the time (and cost) spent on tool logistics and tool changes.
Aluminium alloys can be rough and finish machined extremely easily at high feed rates. However, process reliability and surface quality are influenced by chip removal and the formation of cavities. Added to this are the numerous cavities found on engine blocks, such as drilled holes, bushes and recesses. Of course, cleaning routines – an additional process step - add to overall production costs and does not guarantee that all chips can be removed.
Walter’s answer has been to design the new cutter with a coolant channel running through the centre of the tool, ensuring that the flow of coolant removes any chips.
An additional factor is the cavities that form during casting, which are ‘ripped open’ during milling and, if untreated, can result in leaks. Again, an additional milling operation is traditionally required to create a homogeneous finish where the porous surface is ‘filled in’. The new cutter overcomes this problem by being able to perform both finish- and lubricated-milling.
