1. Differences in chemical composition
| Trace element W% | Aluminum content: balance | |||||||
| Silicon Si | Iron Fe | Cu | Manganese Mn | Magnesium Mg | Zinc Zn | Metal Ti | Chromium Cr | |
| 6061 | 0.4-0.8 | 0.7 | 0.15-0.4 | 0.15 | 0.8-1.2 | 0.25 | 0.15 | 0.04-0.35 |
| 6063 | 0.2-0.6 | 0.35 | 0.1 | 0.1 | 0.45-0.9 | 0.1 | 0.1 | 0.1 |
The 6-series aluminum alloys are medium-strength heat-treatable alloys. Magnesium has a significant effect on strengthening aluminum alloys, and zinc and copper also have obvious strengthening effects on aluminum alloys.
As can be seen from the above table, 6061 has more alloying elements than 6063. From the content of magnesium and silicon, about 6061 is 30-50% more than 6063. The most direct impact is that the strengthening effect of 6061 is greater than that of 6063.
2. The difference in mechanical properties
material | Tensile strength (MPa) | Tensile strength (MPa) | Hardness (HB) |
6061-T6 | 310 | 275 | 95 |
6063-T5 | 185 | 145 | 60 |
6063-T6 | 230 | 180 | 70 |
We can see from the chemical composition that the trace element content of 6061 is higher than that of 6063. As a 6-series alloy with magnesium and silicon as the main elements, Mg and Si form the strengthening phase Mg2Si. The higher the content of magnesium and silicon, the greater the amount of Mg2Si, and the greater the strengthening effect of heat treatment.
On the contrary, the higher the tensile strength, the higher the deformation resistance, so the plasticity of the alloy will decrease.
Therefore, according to the design value of the tensile strength of the T5 profile, the content of magnesium and silicon should be fine-tuned appropriately to reduce the tensile strength to obtain better plasticity, especially for profiles with complex sections.
3. Comparison of Plasticity
6061-T6 is used in occasions that require a certain strength and hardness. 6063 is a representative alloy for extrusion and has good extrudability.
Especially 6063-T5 has excellent thermoplasticity, and can be extruded into various profiles with complex structures (such as thin-walled and hollow ) at high speed or forged into forgings with complex structures. It has a wide quenching temperature range, low quenching sensitivity, and extrusion After pressing and forging demoulding, as long as the temperature is higher than the quenching temperature. That is, it can be quenched by spraying water or piercing water.
4. Other comparisons
Surface treatment: 6061 and 6063 have good oxidation performance. The surface adhesion of 6063 aluminum alloy is slightly higher than that of 6061 aluminum plate, so the oxidation ability is extremely strong.
Machinability: Good overall, 6061 is better.
Corrosion resistance: generally very good, 6063 is slightly better.
Weldability: All can be welded, 6063 is slightly better.
Price: The price of the two is about the same, currently 6063 is slightly more expensive.
To put it simply, the advantage of 6061 is strength, while 6063 wins in extrusion shape; you can choose the most suitable product according to its performance characteristics.
Could 6061 or 6063 be the right choice for your next metal fabrication project? Jiangsu Tisco Steel Co., Ltd. are metal fabrication experts with over of experience, and we are ready to answer any questions you have. Contact us today for a quote or to chat with an expert!