An automotive lamp mainly consists of a frontal lens, reflector, and housing. The lamp reflector forms a beam of light from the bulb by reflecting them. In this case, it increases the intensity of the light by reducing its scattering. This part is usually half-round or conic shape. The surface is often coated by an aluminum layer. Why aluminum? Because it has good heat dissipation performance.
When making a lamp reflector prototype, there are two manufacturing solutions. One is to make the part in plastic material and then do electroplating. Another is to make it by CNC machine as aluminum parts directly, which is more high-end looking. In this case, we would like to show some lamp reflectors by CNC machine, the aluminum parts.
Aluminum's hardness is very low among other metals, so it is suitable for CNC machining. How to choose CNC machines for specific aluminum parts? The following factors need to take into consideration.
- Size of the aluminum part. It determines the working range of the CNC machine.
- Processing requirements. Although most CNC machining centers are suitable for processing aluminum parts, there are different processing requirements for each part. Some require higher accuracy and finer finishing, and some don't need tight tolerances.
In these cases, the customers requested to use aluminum 6061-T6 with high machining accuracy and high-quality surfaces. We used a 3-axis CNC machining center to meet these requirements. It is a JIRFINE VH-85 Vertical Machining Center with the following capacities:
- 40 Taper, 15,000-rpm Spindle, 24 Tool Capacity
- Maximum Machining Size: 850×550×550 mm
- Rapid Traverse Speed: 36m/min
- Max Cutting Speed: 20m/min
- Pointing Accuracy: ±0.005 mm
Aluminum lamp reflector parts are usually not large. A CNC machining center for small and medium-sized parts is enough. Machining metal parts via CNC machining, including aluminum parts, requires a high turning speed. The technicians at X Rapid Technologies excel at clamping the tools and controlling the tool speed and temperature to guarantee high tolerances and high-quality surfaces.
In cases of making larger CNC machined aluminum parts, we can use our Hass VF-4SS-V Vertical Machining Center which has a maximum machining size of 1270×508×635 mm. Our CNC machines enable us to meet various custom machining requirements of our clients.
CNC machined aluminum lamp reflector parts without finishing
To keep the optical features, it is suggested not to do a surface treatment like polishing. Otherwise, the sharp corner would become round, which results in reflecting fewer lights.
CNC-machined aluminum lamp reflector parts with electroplating
Sometimes, to make the reflector more aesthetic and looks like an end product, we will electroplate the aluminum lamp reflector prototype to gain a high glossy surface.
The advantages of producing aluminum parts through CNC machines
1. It massively reduces the number of tools. The processing of the complex shape of aluminum parts does not need complex tools. The processing program can be modified to change the size and shape of the part, which is suitable for developing new products and reshaping existing ones.
2. Stable machining quality, high machining accuracy, and high repeatability.
3. For multi-type and small-batch production, CNC machining is highly productive. It can reduce the time of production preparation, machine tool adjustment, and process inspection. Using the best cutting volume reduces cutting time.
4. It is possible to process complex aluminum profiles that are difficult to process by conventional techniques, and even to process parts that cannot be observed.
Materials for CNC machined aluminum parts
The AL6061-T6 used in the above cases is one of the most popular aluminum alloys on the market, and most manufacturing companies use it as a standard grade for CNC machining. It is versatile and easy to machine, and AL6061 can even be heat treated in different ways.
AL6061-T6 is an excellent general-purpose material for a variety of use cases. Although it has a good strength-to-weight ratio, it is unsuitable for high-stress applications. Common applications include automotive parts such as chassis, bicycle frames, valves, computer parts, etc.
Aluminum materials are classified as Rolled (sheet, plate, coil, strip), Extruded (tube, solid bar, profile), and Cast. The aluminum materials suitable for CNC machining are aluminum alloy plates with the following types and applications.
Pure Aluminum Alloy (1000 Series)
They contain more than 99% aluminum. Despite their electrical conductivity, corrosion resistance, welding performance, and low strength, they are not heat-treatable reinforced.
Applications: mainly used in scientific experiments, the chemical industry, and other special applications.
Aluminum-Copper Alloy (2000 Series)
An aluminum alloy containing copper as the main alloying element, manganese, magnesium, lead, and bismuth will also be added. Their machinability is good, but they are prone to intergranular corrosion.
Applications: aerospace industry (AL2014), screws (AL2011), and industries with high operating temperatures (AL2017).
Aluminum-Manganese Alloy (3000 series)
With manganese as the main alloying element, it has good corrosion resistance and good welding performance. The disadvantage is low strength, but it can be improved by cold working hardening. It is easy to produce coarse grains when annealed.
Applications: seamless oil guide tubes used in aircraft (AL3003), easy-to-pull cans (AL3004).
Aluminum-Silicon Alloy (4000 series)
They are silicon-based and have high wear resistance, low coefficient of thermal expansion, easy to cast. Less or higher silicon content will affect the performance.
Applications: widely used in pistons and cylinder blocks of motor vehicles, etc., more applications abroad.
Aluminum-Magnesium Alloy (5000 series)
They are mainly composed of magnesium. They have good resistance and endurance, good welding performance, good fatigue strength, no heat treatment to strengthen, and only cold working to improve the strength.
Applications: lawn mower handle, aircraft fuel tank duct, bulletproof vest, etc.
Aluminum-Magnesium-Silicon Alloy (6000 series)
They are magnesium-&-silicon-based. Their characteristics include medium strength, good corrosion resistance, good welding performance, good process performance, and good oxidation coloring performance.
Applications: It is one of the most widely used alloy materials, mainly for the manufacture of transportation parts (such as car luggage racks, doors, windows, bodies, heat sinks, and inter box shells).
Aluminum-Zinc-Magnesium Alloy (7000 series)
Zinc is the main alloy, but sometimes magnesium and copper are added in small amounts. 7005 and 7075 are the highest grade of this series and can be heat treated and strengthened.
Applications: Aerospace (aircraft load-bearing components, landing gear), rockets, propellers, airships, etc.
8000 series. They are mostly used for aluminum foil, not so often used for the production of aluminum rods.
9000 series, an alternate alloy.