Home / Resources / Aluminum Surface Finishing /

What Finish can be done on Aluminum CNC Machining Parts? 





There are actually many ways for aluminum to make a glossy surface. The first common method is to directly anodize the aluminum machined parts, and then polish it. The roughness of the surface is controlled by polishing.
Advantages: The cost is relatively cheap.

1. The requirements for the raw machined parts are relatively high.  If the texture is rough, it will look rough after polishing.
2. Polishing destroys the size, so the polished size is not within the required range. If the dimensional tolerance is very tight, it will cause the polished part to exceed the required tolerance.





Mirror Effect


Mirror means that the product has the same effect as a mirror, and it looks very high-end.
1. The price is relatively high
2. Special attention should be paid to the protection of parts, because slight scratches or bumps will cause the surface to be ugly, which will seriously affect the overall effect of the parts.


  Chrome Plating


The mirror effect of aluminum parts can also be like the effect of electroplating chrome. Compared with direct polishing to become a mirror surface, he has a layer of electroplating. This electroplating layer is a protective layer, which will make the parts wear-resistant. Conventional Rubbing in the hand will not affect the surface, as long as there is no hard object to collide and rub, there will be no scratches.
Advantages: It can achieve a mirror effect and ensure good wear resistance.
Disadvantages: The cost will be higher than that of direct anodizing and mirror polishing, because there are certain basic requirements for material parts, and then electroplating


Hard Anodizing


If not required, anodizing is normal anodizing. What is the difference between normal anodizing and hard anodizing? That is coating thickness, and normal anodizing will probably be less than 10μm. Hard anodizing is normally above 20μm. The higher the value, the higher the wear resistance and the higher the cost. The cost of normal anodizing is relatively low, and it only plays a role in anti-corrosion, but its wear resistance is not as good as hard anodizing. If our customers require a higher thickness, we will use hard anodizing, and the cost will be higher than normal anodizing.Normal anodizing and hard anodizing are basically indistinguishable from the naked eye, and only professional testing instruments, such as coating thickness gauges. In addition, you can also use 2B pencil to do the friction testto distinguish whether it is hard anodized or normal anodized.


  Color Anodizing


There are camouflage and gradient, and ordinary single color anodizing, the most common is single color anodizing, there are many choices of single color anodizing colors, which can be made according to the customer's panetone number. Various colors is available. However, the whole process of gradient color is different, and the requirements will be relatively high. It is completed after many times of anodizing, and finally many colors will be placed on a product to achieve the effect of gradually changing color, and its cost will also be relatively high. Another kind of anodizing effect is camouflage color. Camouflage color is also made from monochrome through a special process. Its texture is not reproducible, and the randomness is relatively strong, because it is made by a special process.




This kind of surface treatment is suitable for parts that do not have high requirements on size, because the paint is also relatively thick, which has a certain impact on the size, but the colors are various, which can achieve a bright surface effect, but there is no metallic texture after painting. So the limitations are relatively large.


  Powder coating


The price is relatively favorable, but it has a greater impact on the size of the product, because the thickness of the powder coating is relatively thick. This surface treatment can prevent oxidation of aluminum parts, and the cost is relatively low.


Water Transfer Printing


This is a kind of film attached to the surface of the product. Some patterns such as characters or flowers and birds can be produced on the film. This pattern is very controllable, and you can choose to customize various patterns to attach it. In the production process of water transfer printing, the requirements for the entire working environment will be relatively high, because a little dirty spot will cause the product to be scrapped, and the cost will be relatively high.




If you want the product to have better corrosion resistance and a certain metal texture, then we will use electrophoresis. Electrophoresis can ensure the corrosion resistance of the product, and it is similar to the effect of painting, but the metal texture will also be better than The effect of spray painting, and the cost will be more moderate, but the metal texture will be much worse than the effect of anodizing, The paint is attached to the surface and will cover a metal texture, but electrophoresis does not require the surface finish of the product too high.



Iron sand
Advantages: Iron sand is the cheapest and most durable.
Disadvantages: If it is used for a long time, it will be easy to rust. Because it will not be replaced frequently, it will cause the product to be sprayed and dirty. It is suitable for products that are generally not very strict on quality and appearance. 
Glass Sand
Advantages: medium price.
Disadvantages: The effect will be uneven in thickness. Because the glass sand is easily broken, so it will cause the sand to be used for a period of time, the size will be different, and the sand will be uneven, which will lead to long-term irregular use for a period of time.Then it is need to replace, in order to ensure this quality.
Zirconium sand: The best effect of these three common sands. It is the most delicate and has the best texture, but its cost is also very high. Usually, most products will not use this kind of zirconium sand. Unless for special electronic product, such as a case like an iPhone, this zircon sand will be chosen to be made to reach good looking.
Uncommon sands include: quartz sand, plastic sand, etc. These are not commonly used, but they are for special products, such as some titanium alloy products, which cannot be sprayed with iron sand, because they will spark when sprayed , will result in injury to the operator.
Sandblasting is a process to make this product achieve a better consistency, make roughness on the surface of the product, and increase roughness. It's like we choose different roughness for different products, then we need to make them according to cutsomer's requirements. We are more commonly used in this kind of mechanical parts,and equipment parts. Then we will choose  50 , 80 or 100 mesh, etc., These types are a bit rough, basically they do not have very strict requirements on the surface of the product, so quality is the main thing, and the overall consistency of the product will be better after making them.
Ordinary products: For some commonly used electronic products, most of them are in 120 mesh and 150 mesh. For example, 150 mesh belongs to a medium-to-high-end product, and the overall look will be more better. Generally, the customer has appearance requirements for this product, and need to cover the machining marks on the surface, then 150 mesh will be choosen.
High-precision products: For some high-precision products, they have very delicate requirements on the appearance. In addition to the requirements for the surface of this product during our usual processing, we also choose finer one when sandblasting and roughening. Such as the 180 mesh sand we usually use, has high requirements on the surface of the product, and the sand will be fine. It looks very high-end, for example, compared to the shell of this kind of iPhone that we usually use, that is 220 mesh sand At the beginning, which basically has no roughness and is very small.But the cost will be higher than the 120 and 150 we said before, because the production control requirements is very strict compared to those common products.



Latest posts

+86 15099911516