Aluminum is omnipresent. We encounter it in vehicle bodies, aircraft structures, machine components, packaging and in many industrial applications. The reasons for this are obvious: the material is light, malleable, corrosion-resistant and impresses with its excellent conductivity. However, it is precisely this diversity that poses particular challenges for manufacturers. This is because aluminum machining is anything but a matter of course.

Depending on the alloy, strength and structure, it reacts very differently to machining processes. Chip sticking, built-up edge formation and abrupt tool wear are just some of the typical side effects. The challenges often lie in the details and the path to a stable, efficient process is rarely straightforward. What makes the decisive difference only becomes apparent when you delve deeper.

From lightweight to high-performance: What makes aluminum so attractive for machining

As a material, aluminum has an exceptional combination of technical properties that make it particularly attractive for machining. Aluminum naturally forms an oxide layer that protects it from corrosion, and anodizing can further enhance this protection — a clear benefit in harsh environments or for demanding surface requirements. At the same time, aluminum conducts heat and electricity very efficiently: with around 60 percent of the thermal conductivity of copper and an electrical conductivity of around 62 percent at only a third of the weight, it is ideal for lightweight, high-performance components.

The material also offers advantages both visually and functionally. It reflects up to 90 percent of thermal radiation and 80 percent of light, making it predestined for use against light and thermal radiation in applications such as roofing and heat shields for motor vehicles. In terms of sustainability, it scores highly with its excellent recyclability. Recycling uses only a fraction of the energy while maintaining full quality and strength. Furthermore, it generally does not require any additional protective coating, as simple processes such as brushing or shot blasting are usually sufficient. However, if increased protection is required, additional surface treatments such as paints or electrochemical treatments (e.g. anodizing) can be applied.

Light, strong, versatile – ideal conditions for machining

A decisive factor for aluminum machining is the excellent ratio of weight to strength. This makes the material ideal for lightweight, robust constructions, such as in vehicles or aircraft. It also impresses with its uncomplicated processing: it can be produced in almost any desired thickness. Its easy machinability – for example through turning, milling, or grinding – and the high processing speed also make production more economical. Furthermore, it is highly formable and can be processed into fine threads or complex shapes without breakage. Despite its lower ductility compared to copper, its low density and low melting point enable the flexible production of a wide range of products such as sheets, tubes or rods..

Aluminum also shows its strengths at low temperatures: it does not become brittle, but stronger, and remains corrosion-resistant. It is also non-magnetic, which makes it ideal for shielding antennas and computer panels. Anyone who wants to machine aluminum is working with a material that is not only light and conductive, but also robust, sustainable and extremely versatile. Provided you know its characteristics and use the right precision tools, such as those developed by HAM.

Not all aluminum is the same, and that makes all the difference

Aluminum is a real lightweight with amazing strength. Compared to other materials, aluminum is in the middle range in terms of strength. However, when its density is taken into account, it clearly stands out and even surpasses steel. It is precisely this ratio that makes it so attractive for lightweight construction. Aluminum has played a key role in automotive engineering, aviation, and mechanical engineering for many years.

But as versatile as the material is, it also behaves differently when it comes to machining. Because not all aluminum is the same. In addition to pure aluminum, there are a variety of aluminum alloys with their very own properties. While pure aluminum is very soft and only has low strength, alloys usually have significantly better prerequisites for aluminum machining. A distinction is made between wrought alloys and cast alloys. Both types are basically machinable but require a differentiated approach.

In practice, aluminum alloys are divided into three classes. Class one comprises very soft materials with low strength. These often produce greasy chips during machining, which stick to the tool and lead to the formation of built-up edges. Class two describes materials with increased strength in the range of around 300 to 600 Newtons per square millimeter. These alloys are significantly more stable and lead to fewer built-up edges. Class three stands for free-cutting materials and wrought materials with chip-breaking additives such as lead. These additives ensure clean chip formation and significantly reduce the tendency for built-up edge.

The biggest challenges in machining aluminum

At first glance, aluminum seems like a dream partner for machining. Light, easy to shape and clean to process. But when you stand at the machine, you quickly realize that this material also has its peculiarities. In particular, the sticking of chips and the stubborn built-up edge make even experienced machining professionals break out in a sweat. Especially when milling aluminum, these effects can have a negative impact on dimensional accuracy, tool life and surface quality.

One key to successful aluminum machining lies in high-speed machining. Combined with a carefully selected cooling lubricant strategy, many problems can be avoided from the outset. Aluminum generates significantly lower cutting forces than steel during milling, often only about a third. This property allows high cutting speeds, but at the same time requires consistent control of the chip flow.

To ensure process stability, it’s crucial to remove chips from the cutting zone quickly and efficiently. This requires special tools for aluminum with smooth, slippery surfaces that prevent sticking and actively remove the chips. Milling cutters with a lower number of teeth than tools for steel are also characteristic. This design significantly improves the chip flow. Coordinated coating solutions, when integrated into the process, reliably control even sticky aluminum chips.

These are the factors that really matter when machining aluminum

If you want to machine aluminum reliably and precisely, you have to master the interaction of many components. It starts with the machine itself. It should not only work stably, but above all be prepared for the use of modern cooling lubricant solutions. Systems like the AerosolMaster 4000 ATS from Blum-Novotest enable highly efficient minimum quantity lubrication by precisely dosing a fine film of lubricant. At the same time, the machine must support internal and external cooling options and allow clean adaptation to dry machining, emulsion or MQL.

Another cornerstone of aluminum machining is the clamping. The tool holder and workpiece holder must grip precisely to avoid vibrations and ensure clean chip formation. In MQL machining, the cooling channel must be optimally positioned to ensure effective performance. This is the only way to ensure reliable chip removal without leaving any residue in the machining zone. When drilling, for example, a special clamping structure with a central lubricant supply via the holder can be crucial.

And let’s not forget the digital side of the process. CAM programming has a massive impact on efficiency and tool life. Those who rely on well thought-out strategies and smart adjustments to the cutting values not only save time but also ensure uniform surfaces. Those who rely on well-thought-out strategies and smart adjustments to cutting parameters not only save time but also ensure consistent surfaces. Technology such as SolidCAM‘s iMachining, in combination with optimized cutting data, enables a constant load and reduces thermal peaks at the same time.

However, the optimum machine, perfect clamping and intelligent programming only unfold their full potential in combination with the right tool. This is because the cutting material, cutting values, tool geometry and surface technology determine the cutting quality and process stability, especially with aluminum. Therefore, it’s worth taking a closer look at the specific requirements of tools for aluminum machining.

What makes our tools so special when machining aluminum

What truly makes a tool for aluminum machining outstanding isn’t just the cutting material used or a single design feature. It’s the interplay of sophisticated materials, sophisticated geometry, and state-of-the-art surface technology that makes the decisive difference.

When it comes to cutting materials, we specifically focus on two proven materials: polycrystalline diamond (PCD) and solid carbide. PCD tools are the first choice for machining abrasive aluminum alloys with a high silicon content or for very high-volume production combined with long tool life. They are characterized by exceptional wear resistance and deliver consistently high surface qualities – an advantage that is particularly in demand in sensitive sectors such as aviation or automotive engineering.

Solid carbide tools, on the other hand, score points for their versatility. They are ideal for smaller series or for processes that require a high degree of flexibility. Their advantage lies not only in their good cutting performance, but also in the fact that they are generally more cost-effective than PCD tools. They are also a particularly good choice when machining other materials in addition to aluminum, as they are suitable for a wider range of applications.

Geometry and surface technology as the key to performance

The tool geometry is decisive for the quality of machining. Our milling cutters have precisely ground cutting edges, a sharp point and defined cutting edge rounding. Internal cooling channels enable an efficient supply of cooling lubricant, while flat helix angles and uneven helix pitches minimize vibrations and improve chip breaking at the same time. The chip chambers have also been specially designed for aluminum alloys to ensure reliable chip evacuation. The strength of our tools is particularly evident when drilling: The specifically designed MQL chamfer on the cutting edges optimally supports aerosol lubrication and makes the tools particularly efficient in combination with modern MQL systems.

A decisive contribution to tool performance comes from surface technology. In order to meet the high demands placed on PCD and solid carbide tools, HAM has developed Hybrid Surface Finish, or HSF for short, a hybrid and technologically highly complex solution. This produces a defined surface finish while simultaneously homogenizing the cutting edge. In combination with a precisely coordinated grinding quality, this creates a high-performance overall system.

For tools with shank diameters up to 32 millimeters, we apply PVD hard coatings such as TiN, TiAlN, TiNAlOx, or AlOx. The HSF process ensures mirror-smooth surfaces on carbide and PCD, for diameters between 0.5 and 32 millimetres. Depending on the application, defined cutting edge preparations of 4 to 20 µm are achieved. The tool’s meticulous design comes to life only when all its properties are combined optimally, unleashing its full potential.

Machining aluminum – exploiting potential, mastering challenges

Machining aluminum is more than just a routine production step. Different alloys, complex material properties and process-specific requirements demand a high level of expertise. If you want to manufacture economically and reproducibly, you need to have the entire machining process under control – from material selection and the optimum cooling strategy to the precise coordination of machine, clamping and CAM programming. The high quality that modern applications require today can only be achieved if all factors are interlinked.

With our many years of experience in aluminum machining and our highly developed tool solutions – from polycrystalline diamond to finely tuned solid carbide – we not only offer individual components, but also sophisticated overall solutions. Technologically leading geometries, specially developed surface treatments such as HSF and perfectly coordinated coating concepts make our tools the first choice for demanding production tasks. Anyone who wants to machine aluminum efficiently and reliably benefits from our expertise down to the smallest detail.

Practical application

In our workshop “Zerspanung ALU – Best of HAMmer”, we showed how theory and practice can be optimally combined. We machined a component made from the high-strength aluminum alloy EN AW-2017A. This alloy is an age-hardenable material that develops its full strength potential after targeted heat treatment, such as solution annealing with subsequent cold ageing. It plays a key role in the aerospace and defense industry in particular due to its high mechanical strength and good machinability.

The workpiece, measuring 200 x 100 x 25 millimetres, was machined on a Hermle C12U, controlled by a Heidenhain TNC 640. We used a zero-point clamping system from LANG to ensure reliable and repeatable clamping. In combination with a precise tool holder from Diebold based on HSK-A63, a high level of stability was guaranteed.Milling was performed with targeted use of minimum quantity lubrication and classic cooling lubricant, ensuring optimal chip removal and maximizing tool life based on the machining area.

When everything works together, it shows how powerful aluminum can be in the right environment.

Der Beitrag How to achieve perfect aluminum machining: Aluminum machining live in the workshop! erschien zuerst auf HAM Präzision.

Hard machining is the machining of ferrous materials with a hardness of at least 54 HRC. Common hard machining processes include grinding, hard milling and hard turning. Hard milling has become increasingly important in recent years, particularly for components, instead of the time-consuming and costly process of grinding or eroding.

Hard machining now plays a central role in many industries. In toolmaking, precision tools are manufactured that require high hardness and wear resistance for demanding applications. In the automotive industry, it enables the machining of crankshafts, gearbox housings and other components that require not only strength but also maximum dimensional accuracy. The aerospace industry benefits from the production of critical components that have to withstand extreme loads such as high temperatures and mechanical pressure. In medical technology, it enables the precise production of surgical instruments and implants, which not only have to be precise but also biocompatible. It also plays a key role in power generation when processing components for turbines and generators, which have to withstand high loads during operation.

In all of these areas, hard machining is crucial in order to achieve the desired properties of the materials and ensure the functionality of the products.

Advantages of hard machining and hard milling

Hard machining offers numerous advantages for economical and high-quality production. It can replace time-consuming processes such as grinding or eroding and offers significantly higher productivity thanks to shorter throughput times. It also ensures a high surface quality, which noticeably improves the quality and dimensional accuracy of the components.

Hard milling in particular offers decisive advantages that make it a preferred processing method for hard materials. Thanks to its high precision, it enables the production of components with very tight tolerances and a high surface quality – a decisive factor in many applications. The high surface quality reduces the need for subsequent processing steps such as grinding or polishing. At the same time, the fast and efficient processing results in less thermal deformation of the workpiece compared to other processing methods, such as grinding. In addition, hard milling also scores highly in terms of productivity, as in many cases it can be carried out significantly faster than other machining methods.

All these advantages make hard machining an effective and efficient method for machining hard materials in various industrial applications.

From raw material to high-performance steel: Reasons why steel is hardened

The hardening of steels is an essential process to improve their mechanical properties and make them more efficient for specific applications. A key point is increasing the hardness: the hardening process increases the hardness of the steel, making it more resistant to abrasion and wear. This is particularly important for tools and machine components that experience high mechanical loads. At the same time, hardening leads to an increase in strength so that the steel can withstand higher tensile and compressive forces. It also provides increased wear resistance so that they are better protected against mechanical wear, extending their lifespan and reducing the need for frequent maintenance or replacement.

Another advantage of hardening is the improvement in dimensional stability, which ensures that components retain their original geometry even at high temperatures or under mechanical stress. The process also enables adaptation to specific applications. Through targeted hardening, steels can be optimized for special applications, e.g. for use in the automotive industry, in mechanical engineering or in the aerospace industry. Hardened steels also offer increased temperature resistance, which makes them ideal for applications in hot environments. Thus, you can apply hardening steels in various industrial applications that require high performance and reliability.

The hurdles of hard machining

A key difficulty in hard machining is tool wear, as the high hardness of the materials puts a lot of strain on the tools. This requires the use of special, high-strength cutting materials and regular tool changes. At the same time, hard milling generates a considerable amount of heat, which can have a negative impact on both the workpiece and the tool. Insufficient cooling can lead to deformation or premature destruction of the tool. Another problem can be the formation of microcracks that thermal stresses in the material cause. High heat generated during milling causes these stresses. To control them effectively, suitable cooling strategies or optimized cutting parameters are required.

Choosing the right machining parameters – including cutting speed, feed rate and cutting depth – is crucial. Incorrect parameters can lead to poor surface quality or inaccurate dimensions. In addition, machine stability plays an important role: vibrations or insufficient machine rigidity significantly reduce the processing quality. Finally, surface quality remains a key challenge, as machining hard materials often results in rough surfaces that need to be reworked.

Mastering hard milling: Strategies for precise and efficient machining

Numerous challenges arise in hard machining, but one can overcome them using various strategies and techniques. One of these approaches is the selection of the right tools. The use of high-quality carbide or cermet tools specially developed for hard milling can reduce tool wear and improve machining quality. Optimizing the machining parameters can also make a significant contribution. The careful selection of cutting speed, feed rate and cutting depth is crucial. Through tests and simulations, we can determine the optimum parameters that maximize both productivity and surface quality. Efficient cooling is also important to reduce heat generation during milling and extend tool life. In addition, targeted cooling can also prevent deformation of the workpiece.

The use of stable and precise machines is important in order to minimize vibrations. Regular maintenance and calibration of the machines contribute to stability. Sensors and monitoring systems help monitor the machining process in real time. This allows us to detect problems at an early stage and make adjustments. Furthermore, a well-trained workforce is critical to success in hard milling. Training on best practices, tool handling and machine operation can improve machining efficiency and quality. By using CAD/CAM software to simulate the machining process, potential problems can be identified in advance and machining can be optimized. By combining these strategies, we can effectively overcome the challenges of hard machining.

The tools used for hard milling are often made of coated cemented carbide, ceramic or polycrystalline cubic boron nitride (CBN). At high cutting speeds and temperatures, these materials allow for precise cuts due to their exceptional hardness and wear resistance. Manufacturers often coat the tools with special coatings that reduce friction and increase tool life. It is important to choose a carbide substrate that has high hardness and wear resistance. Typically, cobalt-bonded carbides (such as WC-Co) are used as they offer a good combination of hardness and toughness. For special applications, we can also consider other alloys or coatings to optimize performance. It is advisable to consider the specific requirements of the machining and the material to make the best choice.

Hard, harder, HAMazing: The secrets of our tools for hard machining

The right choice of carbide is a decisive factor for success in hard machining. Carbides are primarily classified according to their CO content and the tungsten carbide grain size. A higher cobalt content increases toughness but reduces hardness and wear resistance. In contrast, a lower cobalt content provides greater hardness, but at the same time increases susceptibility to fracture. HAM mainly uses carbide grades with a cobalt content of between 6 and 12 %. The microstructure and structural changes have a significant influence on the properties of carbides. The finer the grain size, the harder the carbide becomes. In order to determine the optimum carbide grades, HAM analyzed around 110 variants in its in-house laboratory.

The grain size of hard metals ranges from less than 0.2 µm in the nano range to over 6.0 µm in the extra coarse grain range. This diversity is accompanied by widely varying material properties. At HAM, we generally use a grain size range from ultra-fine to fine grain, as these meet the high requirements of many tools.It is essential to match the carbide grade carefully to the respective application. Not every grade is suitable for every tool. To ensure the selected carbides meet our high quality standards, they are extensively tested for their physical and metallographic properties in our in-house laboratory.

The geometry of the tool is also an essential component of hard machining. We do everything we can to match it perfectly to the requirements. Various factors are crucial to achieving optimal results. The negative rake angle ensures a stable cutting process even under high loads. At the same time, a reinforced core increases the robustness of the tool. Careful cutting edge rounding or preparation minimizes the risk of breakage and ensures consistent performance. Finally, mirror-smooth surfaces help to reduce friction and achieve an exceptional surface quality on the workpiece. All of these elements work together to maximize the precision and efficiency of hard machining.

To achieve a mirror-smooth surface and to meet the market’s growing demands on PCD and solid carbide tools, HAM has developed a hybrid, technologically highly complex solution – Hybrid Surface Finish (HSF). This method makes it possible to achieve a precisely defined surface quality and homogenize the cutting edges at the same time. An essential factor for the performance of the tools. A precisely coordinated grinding quality defines the basis for success before the surface treatment.

But the proper coating also gives tools decisive advantages in hard machining. This should be wear-resistant, friction-reducing thanks to a smooth coating without droplets and heat-resistant up to 1,100 °C. The most common coatings include TiAlN- / and AlTiN-based coatings. These are available as mono- or multilayers, supernitrides or nanostructures. You can use TiAlN or TiSiN coatings for applications with particularly high temperatures, such as hard machining. In the field of processing non-ferrous metals, so-called rainbow coatings (ta-C coatings) are becoming increasingly popular. However, they can only operate at a temperature up to 550 °C. A high-quality coating is only one part of success. Only the perfect interaction of all aspects makes a tool perfect.

Accept challenges, achieve precision: Our conclusion on hard machining

Hard machining is at the heart of modern manufacturing technologies. From the automotive industry to aerospace and medical technology, machining hard materials opens up a wide range of applications. These applications cover many different industries. However, it also poses considerable challenges. The extreme hardness of the materials leads to high tool wear, while the resulting heat can promote deformation and surface defects. Choosing the optimal machining parameters and efficient cooling are essential to overcoming these difficulties. HAM accepts these challenges and offers solutions that help you to machine the hardest materials with the highest accuracy. The perfect coordination of carbide grades, geometry, surface technology and coating results in tools that meet the highest demands. Let us master the challenges of hard machining together.

Live machining of a connecting rod shape (150 x 150 x 50 mm) through-hardened to 62 HRC (X155CrVMo12-1) as part of our “Hart – Härter – HAMmer” workshop on November 20, 2024

Der Beitrag Precision and efficiency for hard materials: Hard machining live at the workshop! erschien zuerst auf HAM Präzision.

To meet the increasing demands of our customers from now all HAM milling cutters with the coating specification TA-AL will get our NEW rainbow-colored carbon coating.  

To meet the increasing demands of our customers, we will equip all HAM milling cutters with the TA-AL coating specification. We will use our NEW rainbow-colored carbon coating effective immediately.

This applies to the HAM types 40-1001, 40-1041, 40-5351, 40-5460 and 40-5860.

The new carbon coating offers high hardness, excellent wear resistance, self-lubricating properties, an extremely smooth surface, and a coating thickness of up to 1 µm.

With the sharper cutting edges the tools are particularly suitable for machining all non-ferrous metals such as aluminium, brass, copper, etc. They are also suitable for plastics and fiber-reinforced plastics.

This thin coating delivers maximum sharpness of the cutting edge and an extremely smooth surface. This improves chip removal, dissipates heat from the cutting edge and reduces built-up on the cutting edges. 

We are switching our current production to the NEW rainbow-colored carbon coating effective immediately.

We will sell existing inventory first before making the new TA-AL rainbow version available.

Do you have any questions? Feel free to contact us at any time!

Der Beitrag Not only an optical highlight – the new rainbow-colored carbon coating from HAM erschien zuerst auf HAM Präzision.

Special-polishing process HYBRID SURFACE FINISH

With the new Hybrid Surface Finish HAM is launching a polishing process in which all tool surfaces are hyper smooth polished with defined and reproduceable main and secondary cutting edge preparation.

HAM has been developing high-performance tools for the machining of all conventional materials for many years. This also includes modern materials such CFRP, titanium, honeycomb, aluminium and composite sandwich materials.

One of the biggest challenges with modern materials is the machining. For example, CFRP is highly abrasive and titanium is a long-chipping material with very poor thermal conductivity. The result is a very high temparature on the tool cutting edge, which leads to enormous tool wear and consequently also to a shorter tool life.

However, temperature developments on the cutting tool and in the workpiece to be machined have to be avoided. Another goal is to avoid built-up edges – i.e. material adhesion or welding on the cutting edge of the tool and stuck of chips in the flute which would lead to a tool breakage.

For the cutting tool the following factors determine success or failure:

• The best tool geometry in appropriate grinding quality (depending on material and application)
• Die The polishing of the flute for an optimal chip removal (reduction of friction forces)
• Preparation and homogenization of the cutting edge, designed for the material (protection of the cutting edge, prevention of built-up edges)
• Wear protection coating (to reduce generation of heat and increase life cycle time)

To meet the market requirements, HAM has developed a hybrid technologically highly complex solution for surface treatment – Hybrid Surface Finish. With this treatment a reproducible and process-safe cutting edge homogenization takes place with simultaneous polishing of all tool surfaces in the cutting area.

Here you can find our brochure on HSF – Hybrid Surface Finish

Are you interested? Please contact us!

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