Product category:
Tooling materials and inserts
News Release from: Mapal | Subject: PCD blades for high volume machining aluminium
Edited by the Manufacturingtalk Editorial
Team on 29 April 2004
Precise and repeatable geometry aids
chip removal
Highly accurate and repeatable chipbreaker and chip groove geometry overcomes chip removal problems, particularly with wrought aluminium, when machining at high metal removal rates.
The trend towards lightweight design has significantly increased the amount of aluminium components in vehicles over the last few years Because of the extremely high cutting speeds and long tool life, PCD blades have taken up a prominent position in this sector of metal cutting
This article was originally published on Manufacturingtalk on 22 Apr 2004 at 8.00am (UK)
Related stories
Form milling cutters offer 30% time saving
Wear-resistant PCBN form milling cutters produce such high surface qualities that the time spent for final manual polishing can be reduced by 30 to 50%.
Tool clamping cartridges fit minimal lubrication
To put minimal lubrication quantity technology into practice, many institutes and research groups have dealt with specific questions and solutions, but a tool supplier claims to show the way.
The high metal removal rates frequently lead to problems in removing chips, particularly with wrought aluminium which produces long chips.
With cast aluminium the way the chip fractures is not so critical but reliable chip removal still needs to be ensured, for grooving etc.
The following examples will show how Mapal deals with the critical areas mentioned above.
Further reading
New multi-functional tools perform nine operations
Slide actuating tools simultaneously machine and completely finish machine two pre-machined cylinder bores on two separately driven and controlled feed and spindle units.
High performance reamers reduce machining times
High performance reamers' high cutting speeds and, because of the multiple cutting edges, very high feed rates bring extremely good reductions in machining time.
Multi-bladed tools hard machine CVT components
Hard machining is performed in continuously variable transmission components using single and multiple bladed reamers with replaceable heads are used with PCBN cutting edges.
Pumps for hydraulic control and regulating circuits are frequently made of wrought aluminium alloys with a silicon content of less than 1%.
As a result the chip breaks very badly.
Chip fracture therefore needs to be improved on the tool side - by means of appropriate, highly accurate and repeatable chipbreaker and chip groove geometry on the blade.
A new method has been developed at Mapal for producing the required chip geometry precisely.
To introduce high-precision geometry of this kind, the eroding process proved to be too imprecise and could not be repeated with sufficient accuracy.
Mapal therefore developed a new and innovative system for this operation.
For this purpose dimensions need to be extremely precise.
The data for the precisely defined chipbreaker is programmed in 3D design by the development engineer so that the chip moves in a specifically defined direction and breaks in a controlled way immediately behind the cutting edge.
This prevents problems in the machining area.
It improves the quality of the surface of the workpiece and the tool life significantly.
Compared to eroded blades, the new technology offers the decisive advantage that the chipbreaker geometry is produced with a repeatable accuracy.
Unlike wrought aluminium alloys, there is no problem with chips breaking badly in cast aluminium.
The reason for this is the relatively high proportion of Si of approximately 7 to 9%.
Typical workpieces in cast aluminium are modern transmission housings.
However, because of their complicated form, with recesses and angled grooves for seals, bearings, etc, these present other problems: the chips are actually very short but because of the restricted space these are not easy to remove away from the blade.
For these cases Mapal has developed special PCD blades with appropriate geometry which allow chips to be cleared quickly.
Mapal development engineers also have innovative ideas for manufacturing blades for a PCD stepped tool.
Here the customer specified a surface quality of 0.4 micron Ra.
The previous solution with PCD blades without a chipbreaker was not acceptable: the amount of scrap was too high and the tool had a tool life which varied; but above all the chips which were produced could not be cleared quickly enough and this had a negative effect on the surface and concentricity of the bore.
Using the new technology all these difficulties were removed and - as a result - the unit costs were also distinctly reduced.
• Mapal: contact details and other news
• Email this article to a colleague
• Register for the free Manufacturingtalk email newsletter
• Manufacturingtalk Home Page
