Is machined aluminum stronger than cast aluminum?
First of all, machined aluminum usually refers to parts processed from aluminum billets by mechanical processing, such as milling and turning, while cast aluminum is a part obtained by pouring molten aluminum into a mold and cooling it. Next, compare their strengths.
First of all, machined aluminum usually refers to parts processed from aluminum billets by mechanical processing, such as milling and turning, while cast aluminum is a part obtained by pouring molten aluminum into a mold and cooling it. Next, compare their strengths.
1. First of all, consider the material itself. Aluminum has different alloys. For example, the common 6061 and 7075 are commonly used for machining, while cast aluminum may have alloys such as A356 and A380. Different alloys have different compositions, and their mechanical properties are naturally different. For example, the tensile strength of 6061-T6 may be around 310 MPa, while A356-T6 may reach about 260 MPa after heat treatment. It seems that some aluminum alloys used for machining may be stronger. However, if cast aluminum is properly heat treated, its strength may also be close. So here it may be necessary to compare the data of different alloys specifically.
2. The impact of manufacturing process on material properties. There may be defects such as pores and shrinkage during the casting process, which will reduce the strength and toughness of the material. Machining, on the other hand, removes material from a dense billet, reducing the possibility of internal defects and therefore potentially having better mechanical properties. However, casting processes are also improving, such as die casting or investment casting, which can reduce defects and improve material properties. Therefore, the degree of advancement of the process is also a factor.
3. Next is the microstructure. The grain structure formed during the solidification process of cast aluminum may be coarse, which will reduce strength. Machining aluminum usually uses extruded or rolled materials, and these processes will refine the grains and increase strength. However, if cast aluminum is properly heat treated, such as solution treatment and aging treatment, the grain structure can be improved and the performance can be improved. So it is necessary to consider whether it has been heat treated.
4. The application scenario is also an important factor. Casting is suitable for parts with complex shapes, which can be formed in one time and may be less expensive, while machining is suitable for parts with high precision or simpler structures. If the part requires high strength and light weight, a high-strength machined aluminum alloy may be selected; if the shape is complex and the strength requirements are not extreme, cast aluminum may be more suitable. For example, automobile engine blocks are usually made of cast aluminum because of their complex structure, while aircraft parts may be made of machined 7075 aluminum alloy because of the need for high strength.
Under the same alloy grade and heat treatment conditions, machined aluminum is usually stronger because of its dense structure and preferred alloy. However, cast aluminum can also approach machined performance through process improvements (such as semi-solid casting) and heat treatment. The actual choice requires a balance between strength requirements, part complexity, cost, and production batch.