How To Choose The Optimal Precision Machining Technology
It will help you to know how to choose the precision machining technology for your design easily.
As you are a designer, you always learn the skills for designing the great equipments or devices. In order to design out a best equipments or devices, including the function and appearance, you always create many complex construction spare parts. So it is big demand for designer to know all the precision machining technologies. Choosing correct precision machining technology can help designer to design the most effective construction of low cost. Knowing all the precision machining technologies is very important before design. Follow this post to know the different kinds of the precision machining technologies.
Based on the sales price and launched market, you will decide to use carbon steel, stainless steel, aluminum, brass, copper, plastic, titanium. They also have different material designations, different designations mean different performance. Using the best raw Material in precision machining technology, is important.
Due to complex construction, you should choose the most cost effective raw material, although all the parts can be produced by solid bar.
If the parts have a long same size through hole, you can use welding tube or seamless tube.
If the shape is strange, extrusion is a good option for saving cost.
You can also use casting blanks or forging blanks, which need to make a special mold.
It’s the first step. After you buy the raw material, you will receive a long bar or tube, generally 6m long in China. But you piece is much short. So you will use the CNC cutting machine to cut the same size section within tolerance.
When you have enough sections, you will transit them to the CNC turning lathe. CNC turning is only to turning X axis direction, Y axis direction, and the round size. The machined surface roughness is Ra 3.2.
The pieces are usually complex, CNC turning is not enough to finish the shape and all sizes. CNC milling is necessary. CNC milling can turning Z axis direction. Although CNC milling can do the same work as CNC turning, but you’d better separate them in 2 steps. Because CNC turning is much faster than CNC milling on X axis direction turning and Y axis direction turning.
CNC grinding is used to get good tolerance and good surface. Only round surface and flat surface can be used on CNC grinding. After CNC grinding, the tolerance can reach as small as 0.005mm, and the surface roughness can reach as good as Ra 0.6. CNC grinding technology is good for high precise parts, such as shaft, piston, worm gear, etc.
If the drawings have the holes, you can use CNC drilling to drill the holes, instead of CNC turning. CNC drilling is much faster than CNC turning.
If the workpiece needs thread hole, you can use CNC tapping machine to tap the hole. It is cost saved process.
Sometimes, you will use carbon steel, aluminum or brass, you must do surface finish to protect the surface after precision CNC machining technology. Many of the parts are assembled outside for appearance, surface finish is also necessary.
After all precision machining technology processes, you should remove the burrs. Burrs will hurt the workers or consumers. Shot blasting is most common technology for removing burrs specially.
If your parts’ appearance is very important, you can use polishing to get brushing surface or mirror surface. Brushing surface likes satin and mat, mirror surface likes mirror and shiny.
After all precision machining technology processes, shot blasting or polishing, surface of the parts will be very dirty. Ultrasonic cleaning machine can clean the parts’ surface very clearly. 2 times ultrasonic cleaning is necessary.
Heat treatment is not for all raw materials. Only carbon steel and stainless iron can do heat treatment to have good hardness. In China, there are two kinds of heat treatment, Net belt furnace heat treatment and vacuum heat treatment.
Zinc plating includes cold zinc plating and hot-dip zinc plating.
The resistance to corrosion of hit-dip zinc plating is much better than cold zinc plating,
The zinc layer thickness of hot-dip zinc plating is about 30μm-50μm, the zinc layer thickness of cold zinc plating is about 12μm. Obviously, the cost of cold zinc plating is cheaper than hot-dip zinc plating. You can get different colors for zinc plating, for example, black, blue, white, rainbow, etc.
Nickel plating is also cold electroplating. The resistance to corrosion of nickel plating is much better than zinc plating, but a bit worse than hot-dip plating. Compared to hot-dip plating, the surface roughness of nickel plating will be smoother than hot-dip zinc plating, cost effective as well. Nickel plating has two colors, one is black, and the other is yellow.
Chrome plating includes brass chrome plating and nickel chrome plating. Brass chrome plating is usually used for decoration, it’s shiny and cheap. Nickel chrome plating is usually used for tools or equipments’ spare parts. The resistance to corrosion and wear resistance of nickel chrome plating are better. Chrome plating have two colors, one is black, and the other is silver.
Real gold plating is very expensive plating. It is usually used for jewelry or speaker’s spare parts. It includes 18K gold plating and 24K gold plating. The color of 18K gold plating is shiny pale yellow, and the color of 24K gold plating is deep yellow. 24K is much more expensive than 18K.
Titanium plating can increase the wear resistance very much. Most high level tools use titanium plating. You can do many colors for titanium plating, including rose gold, titanium gold, Champaign gold, coffee gold, black gold, rainbow, sapphire, bronze gold.
A thick copper layer and a thin nickel layer are used as protective decorative coatings. The copper coating has a significant effect on improving the bonding force between the substrate and the coating and improving its corrosion resistance. Because the copper plating layer is relatively soft, especially the bright acid copper sulfate plating layer is softer, which can greatly improve the toughness of multi-layer plating; the excellent leveling performance and bright performance of the bright acid copper plating layer make it basic to the workpiece before plating The polishing roughness requirements of the machine are greatly reduced.
PVD is the abbreviation of Physical Vapor Deposition in English, which means “physical vapor deposition” in Chinese. It refers to a thin film preparation technology that uses a physical method to deposit materials on the workpiece to be plated under vacuum conditions. PVD has the characteristics of high hardness, high wear resistance (low friction coefficient), good corrosion resistance and chemical stability, and the film has a longer life; at the same time, the film can greatly improve the appearance and decoration performance of the workpiece.
Black oxide is cheap surface finish to improve the rust resistance. But the layer is thin, it can be removed easily during transit. It is not good for sea shipment.
Electrophoresis (Electrophoresis, EP) is the abbreviation of electrophoresis phenomenon, which refers to the phenomenon that charged particles move towards the opposite electrode under the action of electric field. The technique that uses different moving speeds of charged particles in an electric field to achieve separation is called electrophoresis.
Phosphate is better than black oxide. Normally, you can use phosphate instead of black oxide. Phosphate is common used on tools. There two kinds of phosphate, black phosphate and grey phosphate. The difference is not only colors, the rust resistance of black phosphate is better than grey phosphate. Black phosphate is more expensive.
Powder coated is a surface finish method for spraying plastic powder on parts. Sprayed products are mostly used in boxes used indoors, and the paint film presents a flat or matte effect. all different colors are available.
Painting is similar to powder coating. But the layer of painting is thinner than powder coating. all different colors are available too.
It is usually used for stainless steel to increase the wear resistance.
Anodizing has two kinds, one is common anodizing, and the other is hard anodizing. The layer of common anodizing is about 10μm, the layer of hard anodizing is about 50μm. Hard anodizing can pass 720 hours UV test.