How to Solve Deformation Problems in CNC Machining of Aluminium Alloys?10 Efficient Strategies Explained

Aluminium alloy has become a commonly used material in CNC machining due to its light weight, high strength and high thermal conductivity. However, aluminium alloys are prone to deformation during machining due to material properties, machining stress and other factors, which directly affects part accuracy and yield. In this article, we will analyse the root causes of deformation in aluminium alloy machining, and provide 10 practical solutions to help you optimise the machining process and reduce the scrap rate.

I. Core causes of aluminium alloy machining deformation

Before developing solutions, you need to understand the key factors that lead to deformation:

Material properties: Aluminium alloy has a high coefficient of thermal expansion and is susceptible to temperature changes during processing.

Residual stresses: internal stresses remaining in the rolling or casting process of the raw material are released after machining, leading to deformation.

Cutting force and heat: tool friction and cutting force generate local high temperature, triggering local expansion or contraction of the material.

Improper clamping: Unreasonable design of fixture leads to uneven force on the workpiece, exacerbating the risk of deformation.

II. 10 strategies to efficiently solve the deformation of aluminium alloy CNC machining

1. Optimise material pre-treatment

Strategy: Stress relief annealing treatment of aluminium alloy blanks before machining (temperature: 300-400 ℃, holding time 2-4 hours).

Effect: Eliminate the internal stress of raw materials and reduce the probability of deformation after machining.

Applicable scenes: high-precision thin-walled parts, complex structural parts.

2. Selection of special tools and coatings

Tool selection: use multi-flute diamond coated milling cutter (e.g. PCD cutter) to reduce cutting heat.

Parameter optimisation:

Cutting speed: 500-800 m/min (carbide tools) or 2000-3000 m/min (PCD tools).

Feed: 0.05-0.15 mm/tooth to avoid surge of cutting force due to excessive feed.

3. Layered machining and symmetric cutting

Layered machining: break down the deep groove or thick-walled structure into multiple processes, each layer of the cutting depth of not more than 0.5 times the diameter of the tool.

Symmetric cutting: alternate feed from both sides of the workpiece, balanced cutting force distribution (for thin plate parts).

4. Control processing temperature

Cooling method: adopting high-pressure spray cooling or liquid nitrogen cooling to avoid excessive temperature difference caused by traditional water cooling.

Temperature monitoring: install infrared thermometers in key processes to monitor the temperature of the workpiece in real time (it is recommended to control the temperature below 60 ℃).

5. Optimise clamping design

Clamp type: Use vacuum clamps or multi-point flexible clamps to reduce local pressure concentration.

Support design: add auxiliary support structure for thin-walled parts (chemically or mechanically removed after machining).

6. Use of dynamic machining paths

CAM programming techniques:

Use spiral feeds or circular cuts to reduce cutting impact.

Avoid sharp tool stops at corners and switch to adaptive smoothing paths.

7. Post-treatment process

Vibratory ageing treatment: Apply high frequency vibration to the part after machining to release residual stresses.

Cold press correction: Use hydraulic press to fine-tune parts with slight deformation.

8. Material selection optimisation

Recommended grades:

6061-T6: excellent comprehensive performance, suitable for general structural parts.

7075-T651: High strength, suitable for aerospace precision parts.

5052-H32: strong deformation resistance, suitable for thin plate processing.

9. Dynamic adjustment of processing parameters

Adaptive control system: real-time feedback of cutting force data through sensors, automatic adjustment of feed rate and spindle speed.

10. Test cutting verification before batch machining

Trial cutting process:

Use low-stress cutting parameters to machine the first piece.

Detect the deformation amount by Coordinate Measuring Machine (CMM).

Reverse correction of CAM programme based on the data.

III. JLCCNC's Aluminium Alloy Machining Solutions

At JLCCNC, we focus on solving difficult aluminium alloy machining problems, and are especially good at precision manufacturing of thin-walled and complex curved parts. Our service advantages include:

Technical guarantee:

Adopting imported 5-axis CNC machine tools to ensure machining stability.

Equipped with high-pressure cooling system and online thermometer, real-time control of processing temperature.

Process experience:

Customised stress relief solutions for different aluminium alloy grades (e.g. 6061, 7075).

Provide technical support from material pre-treatment to post-treatment.

IV. Summary

Aluminium alloy processing deformation problems need to be solved systematically from the material, process and equipment. By optimising pretreatment, tool parameters, clamping design and post-treatment process, the risk of deformation can be significantly reduced. If you need high-precision, low-deformation aluminium alloy parts machining services, JLCCNC will provide you with professional support to help you break through the manufacturing bottleneck and enhance product competitiveness!