What is the Aluminium CNC Machining Processes?
You can perform aluminum machining using various CNC machining processes available today. Some of these processes include:
CNC Turning:
In CNC turning operations, the workpiece rotates, while the single-point cutting tool stays stationary along its axis. Depending on the machine, either the workpiece or the cutting tool carries out feed motion against the other in order to achieve material removal.
CNC Milling:
CNC Milling operations are the most commonly used in machining aluminium parts. These operations involve the rotation of a multi-point cutting along its axis, while the workpiece stays stationary along its own axis. The cutting tool, the workpiece, or both move to create the feed motion that achieves cutting action and removes material along multiple axes.
Pocketing:
Also known as pocket milling, pocketing is a form of CNC milling in which a hollow pocket is machined in a part.
Facing:
Facing in machining involves creating a flat cross-sectional area on the surface of a workpiece through either face turning or face milling.
What Are the Most Critical Quality Control Measures for Ensuring the Dimensional Accuracy and Consistency of Machined Aluminum Parts?
Precision Machining Processes:
First Article Inspection (FAI):
In-Process Inspection:
Post-Process Inspection:
Quality Management Systems:
What Are the Latest Advancements in Inspection Technologies for Aluminum Machining?
In-Line Metrology:
Automated Defect Detection:
Non-Contact Measurement:
Data Analytics and AI:
What’s the Popular Aluminum Alloys for CNC Machining?
From our experience at Welle, the following 5 aluminium grades are one of the most often used for CNC machining.
EN AW-2007 / 3.1645 / AlCuMgPb
Alternative designations: 3.1645; EN 573-3; AlCu4PbMgMn.
This aluminium alloy has copper as its main alloying element (4-5%) of copper. It is a short-chipped alloy that is durable, light, highly functional, and has the same high mechanical properties as AW 2030. It is also suitable for threading, heat treatment, and high-speed machining. All these properties make EN AW 2007 widely used in the production of machine parts, bolts, rivets nuts, screws, and threaded bars. However, this aluminium grade has low weldability and low corrosion resistance; therefore it is recommended to carry out protective anodising after part machining.
EN AW-5083 / 3.3547 / Al-Mg4,5Mn
Alternative designations: 3.3547; Alloy 5083; EN 573-3; UNS A95083; ASTM B209; AlMg4.5Mn0.7
AW 5083 delivers excellent performance in severe environments. Its magnesium content and small traces of chromium and manganese give it very high resistance to corrosion in chemical and marine settings. Among non-heat treatable alloys, AW 5083 offers the highest strength, which it retains even after welding. Although it should not be used above 65°C, it excels in low-temperature applications.
Manufacturers use AW 5083 in many applications, including cryogenic equipment, marine vessels, pressure equipment, chemical processing, welded constructions, and vehicle bodies.
EN AW 5754 / 3.3535 / Al-Mg3
Alternative designations: 3.3535; Alloy 5754; EN 573-3; U21NS A95754; ASTM B 209; Al-Mg3.
EN AW-6060 / 3.3206 / Al-MgSi
Alternative designations: 3.3206; ISO 6361; UNS A96060; ASTM B 221; AlMgSi0,5
This is a magnesium and silicon-containing wrought aluminium alloy. It is heat-treatable and has average strength, good weldability, and good formability. EN AW 6060 offers high corrosion resistance, which anodising can further enhance. Manufacturers often use it in construction, food processing, medical equipment, and automotive engineering.
EN AW-7075 / 3.4365 / Al-Zn6MgCu
Alternative designations: 3.4365; UNS A96082; H30; Al-Zn6MgCu.
Zinc is the primary alloying element in this grade of aluminium. Although EN AW 7075 has average machinability, poor cold forming properties, and is not suitable for both welding and soldering; it has a high strength-to-density ratio, excellent resistance to atmospheric and marine environments, and strength comparable to some steel alloys.
EN AW-6061 / 3.3211 / Al-Mg1SiCu
Alternative designations: 3.3211, UNS A96061, A6061, Al-Mg1SiCu.
This alloy contains magnesium and silicon as its major alloying elements with trace amounts of copper. With a tensile strength of 180Mpa, this is a high strength alloy and is very suitable for highly loaded structures such as scaffolds, rail coaches, machine and aerospace parts.
EN AW-6082 / 3.2315 / Al-Si1Mg
Alternative designations: 3.2315, UNS A96082, A-SGM0,7, Al-Si1Mg.
Typically formed by rolling and extrusion, this alloy has medium strength with very good weldability and thermal conductivity. It has high stress corrosion cracking resistance. It has a tensile strength that ranges from 140 – 330MPa.
What’s the Post-machining Processes of Aluminum Machined Parts?
After machining an aluminium part, there are certain processes that you can carry out to enhance the physical, mechanical, and aesthetic features of the part. The most widespread processes are as follows.
Bead and Sand Blasting:
Bead blasting is a finishing process for aesthetic purposes.
It gives aluminium a satin or matte finish. The main process parameters for bead blasting are the size of the glass beads and the amount of air pressure used. Only use this process when the dimensional tolerances of a part are not critical.
Other finishing processes include polishing and painting.
Coating:
This involves coating an aluminium part with another material such as zinc, nickel, and chrome. This is done to improve the parts processes and may be achieved through electrochemical processes.
Anodising:
The anodising process uses an electrochemical method where technicians dip an aluminium part into a solution of diluted sulphuric acid and apply an electric voltage across the cathode and anode. This process effectively converts the exposed surfaces of the part into a hard, electrically non-reactive aluminium oxide coating. The density and thickness of the coating created is dependent on the consistency of the solution, the anodising time, and the electric current. You may also carry out anodisation to colour a part.
Powder Coating:
The powder coating process involves coating a part with colours polymer powder, using an electrostatic spray gun. The part is then left to cure at a temperature of 200°C. Powder coating improves strength and resistance to wear, corrosion, and impact.
Heat Treatment:
Parts made from heat-treatable aluminium alloys may undergo heat treatment to improve their mechanical properties.
Where of the Applications of CNC Machined Aluminium Parts?
As stated earlier, aluminium alloys have a number of desirable properties. Hence, CNC-machined aluminium parts are indispensable in several industries, including the following: