Difficulties and precautions in precision machining of aluminum alloys

Aluminum alloy is the main processing raw material in machining factories. It is widely used and easy to process. It is one of the mainstream metals, so the precision machining of aluminum alloy has received extensive attention and popularity.

Since every machining factory can process aluminum materials, aluminum alloy CNC processing is a real industry with extremely fierce competition. Every machining factory has to continuously improve its competitiveness in order to maintain its position in the fierce market competition. own share.

• 1 – Main Difficulties in Precision Machining of Aluminum Alloys

If a shop only needs to machine a handful of aluminum parts, then the efficiency of aluminum CNC machining doesn't really matter. However, if a processing plant needs to process tens of thousands of aluminum parts every week, the efficiency of precision machining aluminum alloys is crucial. The main challenge in efficiently machining aluminum is to achieve the maximum aluminum material removal rate while getting the product right.If the temperature is too high, the aluminum will melt and fuse to the knife. So even though aluminum is as soft as tofu and easy to cut, if the chips stick to the cutter it is easy to create a friction welding effect between the chips and the aluminum part. Another difficulty is trembling. When the aluminum parts are rotating at high speed, when the tool meets the aluminum parts, sometimes strong tremors will occur.

• 2 – Machining properties of different types of aluminum alloys

Aluminum 2011 - The softest aluminum alloy, this is the easiest to machine of all aluminum grades. Corrosion resistance is poor, so it usually needs anodizing, but seriously, it's hard to find a material that's easier to machine than 2021. Aluminum 2024 - has a high strength-to-weight ratio, so 2024 aluminum alloy is often used when parts require good tensile strength

It can be machined well, but there is one thing to be aware of: it may chip at the very moment when the tool is at the end of a heavy cut. For example when performing full diameter grooving. So it may be necessary to adjust the toolpath to soften the exit to prevent this.These debris are usually easier to handle and don't stick to the aluminum parts much.

Another thing to watch out for is corrosion. The corrosion resistance of 2024 is very poor, so the lubricating fluid on the surface should be dried quickly after machining. Otherwise, the surface quality of 2024 aluminum parts is not very good.Overall, though, the 2024 is pretty easy to turn and mill.

Aluminum 5052—Also a very soft aluminum material, often used in forming applications. For example, it is used in aluminum casings, or in marine aluminum parts, because 5052 has excellent corrosion resistance.But aluminum 5052 is not as easy to machine because this aluminum alloy is highly viscous and can jam tools quickly.When turning and milling, you need to keep the tools very sharp and well lubricated at all times, otherwise the surface finish of the product will be worn away and the tool will be at risk of damage. If you keep your knives sharp, you can easily achieve a bright mirror finish.

Aluminum 6061—the most commonly used aluminum alloy material, its performance is very balanced in all aspects. It is easy to cut and mill. Basically all machining factories are machining 6061 aluminum. Care should still be taken when withdrawing material in very heavy cuts, there is a slight risk of material chipping.The harder the material, the easier it is to machine. T4 is ideal for machining, with T6 a close second. Compared with the 2011 aluminum alloy, the machinability index of 6061-T4 is equivalent to 90%, while that of T6 is equivalent to 80%.

Aluminum 6063 - Material properties are very similar to 6061, but are more often used in aluminum extrusions. However, 6063 is not that hard. This makes 6063 somewhat difficult to process; it is softer and more viscous.When machining 6063 aluminum profiles, please use very sharp tools and good lubrication at the same time, and pay attention to chip removal.

Aluminum 7075 - This is very popular in structural parts such as aircraft wing spars and bicycle frames. This is a very hard aluminum. Its mechanical properties are very good; the machinability is not as good as 6061, but not worse than 5052. However, it is difficult to obtain a smooth and bright metallic effect on the surface of aluminum 7075 parts; it is more likely to get a smooth but dull gray surface after machining.

In conclusion, all grades of aluminum are highly machinable. In small batch production, machining plants usually do not pay attention to the difference in the machinability of aluminum, only in large batch production, they will pay attention to these things.

Also worth noting is that there is a clear difference between cast and wrought aluminum. Aluminum castings are always stickier, so keep your knives sharp, have extra lubrication and chip evacuation.

The main points of precision machining of aluminum alloy are: keep the tool sharp, good lubrication and pay attention to chip removal.