Empower Your Aluminium Machining

Aluminium und Aluminiumlegierungen sind an sich gut zerspanbar. Weil die Schnittkräfte niedrig sind, erreichen Anwender bei entsprechender Prozessauslegung hohe Schnittwerte und insbesondere auch hohe Standzeiten. Jedoch haben auch Aluminiumlegierungen spezielle Eigenschaften, die es zu beherrschen gilt. Darüber hinaus tragen die Geometrien der Bauteile und die immer höher werdenden Anforderungen an Toleranzen und Prozessfähigkeit zu Herausforderungen in der Zerspanung von Aluminium bei.

Grundsätzlich lassen sich Aluminiumlegierungen in die Hauptbereiche der Gusslegierungen, Knetlegierungen und pulvermetallurgischen Legierungen einteilen, wobei hauptsächlich die zwei erstgenannten für die Zerspanung eine Rolle spielen. Bei den Gusslegierungen werden durch verschiedene Legierungsbestandteile und unter Berücksichtigung des entsprechenden Gießverfahrens die gewünschten Eigenschaften der Bauteile eingestellt. Beim Gießen möchte man so nah als möglich an die Endform des Bauteils herankommen, um die mechanische Bearbeitung zu vereinfachen. Diese „Near Net Shape“ Technologie hat sich insbesondere in der Massenfertigung etabliert. 

Für die Zerspanung gegossener Teile ist bezüglich der Legierungsbestandteile hauptsächlich der Siliziumanteil entscheidend, da dieser stark auf den Verschleiß und die Standzeit Einfluss nimmt. Auch bei den Knetlegierungen werden die gewünschten Eigenschaften durch Legierungsbestandteile entsprechend beeinflusst, wobei der Siliziumanteil hier sehr gering ist, um die spanlose Formbarkeit zu gewährleisten. Um auch hier gute Festigkeiten und Stabilität sowie Dauerfestigkeiten zu erreichen, werden andere Legierungsbestandteile verwendet. Es entstehen kalt- oder warmaushärtbare Legierungen, die zu Halbzeugen verarbeitet und anschließend spanend bearbeitet werden.
 

The aerospace industry deploys MAPAL tools both for part machining – i.e. manufacturing components that are assembled to form sections of the fuselage or wing – as well as for the final assembly where the individual sections of the entire aeroplane are put together.

When part machining aluminium parts, the part is frequently machined from solid material. Machining rates of over 90% call for an efficient volume machining to machine as much raw material in as little time as possible. Powerful tools are key here. The tools must meet a widely variety of requirements in final assembly. Not only is aluminium frequently utilized here, other light-weight materials like titanium and fibre-reinforced plastics are also used in one machining step. These so-called stacks are material combinations that pose a particular challenge as the machining characteristics of the combined materials are very different and the tools have to meet their varying requirements.
 
The aerospace industry has been using aluminium for many years to save weight. Besides the favourable relationship between stability and weight, this material also meets other requirements such as corrosion resistance, fatigue strength and low embrittlement. Therefore, there is high demand for machining solutions for aluminium in part production as well as in final assembly for aeroplanes.
 

One example of special requirements are the electric motor housings. The large stator bore with a diameter tolerance in the IT6 to IT7 range as well as circularity and cylindricity of 20 to 30 µm or less, combined with other functional surfaces for accommodating rotors and transmission elements, requires the highest degree of precision with regards to shape and precision tolerances.

The large battery trays are another example. Their main structure consists of extruded profiles made of aluminium with low silicon content. The challenges here are to keep chip and burr formation under control and to machine the very large parts using economical cutting data without vibration. This also applies to the trend towards mega and giga casting where large-scale structural parts are no longer made of individual parts but are cast as a single piece. The components’ large size and tendency to vibrate call for special tool geometries for low-vibration machining with a high degree of precision. New long-chipping aluminium alloys whose machining characteristics must first be mastered represent a further, related challenge.

Aluminium is also used in many other industries thanks to its properties. Depending on production volume and number of variants, manufacturers use standardised machining solutions for parts where a significant amount of machining is required. Here too there are aluminium parts produced in high quantities, which require very sophisticated customised concepts. In fluid power, for example, parts like pneumatic valve housings and pneumatic cylinders are produced in large quantities. For industries with high variance and small quantity, standardised tool solutions make sense.
 

MAPAL has developed an extensive product and application portfolio thanks to many years of experience and countless proven solutions in the field of aluminium machining. The range includes established bore machining applications like fine boring, reaming and boring. MAPAL’s guide pad technology for fine boring achieves the highest degree of precision for diameter, circularity and cylindricity. For tools with fixed blades for reaming and boring, MAPAL offers a one-of-a-kind range for PCD tools. It includes everything from tools for a single diameter with chamfer to very complex tools for multi-stage bore geometries. For drilling into solid, there is also a large selection of solid carbide drills and drills with indexable inserts. Deep drilling and dry drilling are a particular challenge as special geometries and expertise are required for both.

For the milling of aluminium, MAPAL offers a broad range that includes face milling cutters, high-volume milling cutters, end milling cutters and special designs. Series with cassettes, inserts or a fixed design are available for face milling cutters, for example. PCD and different varieties of carbide are used as cutting material and can be supplied for various cutting depths in combination with the required surface finishes and profiles. In this way special cross-cut structures can be created for sealing faces, for example. In addition to the universally applicable range of end milling cutters made of solid carbide or with PCD blades, MAPAL has products that cater to special requirements such as high precision, parts vulnerable to vibration or high-volume machining.
 

The product range and extensive manufacturing expertise form the basis for optimal machining processes for aluminium parts. But the tool itself is not the only factor. Only through the art of engineering can the wide-ranging product and application portfolio provide the perfect solution. And this is where MAPAL’s true strength lies. Considerable experience developing new solutions time and again for the production of aluminium parts make the tool manufacture a first-class solution provider in this area. And the customer takes centre stage here.

According to the MAPAL philosophy, the perfect solution can only be the one that is precisely tailored to the needs and requirements of the customer. The expectation is not over-engineering but rather machining processes designed based on requirements. MAPAL sees itself as a solution provider and technology partner and, as opposed to a conventional tool supplier, does not only consider technical aspects but also tries to put itself in the customers shoes. This customer-centred focus is behind the “Basic - Performance - Expert” solution approach and enables MAPAL to tailor the tools to the customer’s requirements.