sand casting
Sand casting is known as sand casting and is commonly used to produce precision machined parts in cast iron. At present, with the improvement of domestic sand casting capabilities, especially the improvement of coated sand casting technology, steel, alloy steel, and stainless steel parts have also begun to be produced using sand casting technology.

Advantage:

Suitable for making blanks with complex shapes, especially complex inner cavities;

Wide adaptability and low cost;

For some materials with poor plasticity, such as cast iron, sand casting is the only forming process for manufacturing parts or blanks.

investment casting
Investment casting, also known as lost wax casting, has two main production processes, silica sol casting and water glass casting, which are commonly used to produce stainless steel and alloy steel precision machining parts.

Investment casting refers to making a pattern from a fusible material, covering the surface of the pattern with several layers of refractory materials to form a mold shell, and then melting the pattern and expelling the mold shell, thereby obtaining a mold without parting surfaces, which can be obtained after high-temperature roasting. Casting solutions that can be filled with sand. It is suitable for the production of small parts with complex shapes, high precision requirements, or that are difficult to process, such as turbine engine blades.

Advantage:

High dimensional and geometric accuracy

High surface roughness;

It can cast castings with complex shapes, and the alloys cast are not limited.

centrifugal casting
It is a casting method that pours molten metal into a rotating mold, fills the mold under the action of centrifugal force, and solidifies into shape. Centrifugal casting was first used to produce cast pipes. Centrifugal casting technology is used in metallurgy, mining, transportation, drainage and irrigation machinery, aviation, national defense, automobile and other industries at home and abroad to produce steel, iron and non-ferrous carbon alloy castings. Among them, the production of castings such as centrifugal cast iron pipes, internal combustion engine cylinder liners and bushings is the most common.

Advantage:

There is almost no metal consumption in the gating system and riser system, improving the process yield;
Cores are not needed when producing hollow castings, so when producing long tubular castings, the metal filling ability can be greatly improved, the ratio of wall thickness to length or diameter of castings can be reduced, and the production process of sleeve and tube castings can be simplified;
Castings have high density, few defects such as pores and slag inclusions, and high mechanical properties;
It is convenient for manufacturing composite metal castings such as cylinders and sleeves, such as steel-backed copper sleeves, bimetal rollers, etc. When forming castings, centrifugal motion can be used to improve the metal filling capacity, so thin-walled castings can be produced.

gravity casting
Gravity casting refers to any casting process that uses the gravity of the earth. Liquid metal fills a metal casting mold under the action of gravity and cools and solidifies in the mold to obtain a casting. Different from pressure casting.

Domestic gravity casting generally only refers to aluminum alloy gravity casting.

The advantages are:

Aluminum castings have few internal pores and can be heat treated.

The mold cost is low and the mold has a long service life.

The process is simple and suitable for large-volume operations.

Low flow specialty aluminum alloys can be used.

The material can be used in a wide range of applications.

Lost foam casting (also known as real mold casting)
It is to bond and combine paraffin or foam models similar in size and shape to the castings into model clusters. After brushing with refractory paint and drying, they are buried in dry quartz sand and vibrated to shape. They are poured under negative pressure to vaporize the model and become liquid metal. A new casting method that occupies the position of the model and forms a casting after solidification and cooling. It is suitable for producing precision castings of various sizes with complex structures. There is no limit on the alloy type and the production batch. Such as gray cast iron engine box, high manganese steel elbow, etc.

Advantage:

The casting has high precision and no sand core, which reduces the processing time;

No parting surface, flexible design and high degree of freedom;

Clean production, no pollution;

Reduce investment and production costs.

Forging + machining
Forging precision processing
In recent years, with the development of casting to forging, forging has been increasingly used in the production of precision parts. Our factory also produces many forged precision machining products

Forging is a processing method that uses forging machinery to exert pressure on metal blanks to cause plastic deformation to obtain forgings with certain mechanical properties, shapes and sizes.

Forging can eliminate defects such as loose as-cast metal produced during the smelting process and optimize the microstructure. At the same time, due to the preservation of complete metal streamlines, the mechanical properties of forgings are generally better than castings of the same material.

According to the forging temperature, forging technology can be divided into hot forging, warm forging and cold forging.

The starting recrystallization temperature of steel is about 727°C, but 800°C is generally used as the dividing line. Anything above 800°C is hot forging; between 300 and 800°C is called warm forging or semi-hot forging, which is forged at room temperature. It’s called cold forging. Forgings used in most industries are hot forgings; warm forging and cold forging are mainly used for forging parts such as automobiles and general machinery. Warm forging and cold forging can effectively save materials.

Forging materials are mainly carbon steel and alloy steel of various compositions, followed by aluminum, magnesium, copper, titanium, etc. and their alloys. Iron-based high-temperature alloys, nickel-based high-temperature alloys, and deformed alloys of cobalt-based high-temperature alloys are also forged. Or it is completed by rolling. However, these alloys are relatively difficult to forge due to their relatively narrow plastic zone. Different materials have strict requirements on the heating temperature, opening forging temperature and final forging temperature.

Extruded profiles + machining
Metal extrusion processing is an important method of pressure processing using the principle of metal plastic forming. Through extrusion, the metal ingot is processed into tubes, rods, T-shaped, L-shaped and other profiles at one time. The metal extrusion machine is the most important equipment for metal extrusion processing.

The extrusion process is characterized by a strong three-dimensional compressive stress state, which is beneficial to improving the plastic deformation ability of the metal, improving the quality of the product, and improving the internal microstructure and performance of the product. In addition, extrusion processing also has the characteristics of wide application range, high production flexibility, simple process flow and low equipment investment. The materials most widely used in extrusion processing are non-ferrous alloys with low melting points, such as aluminum and aluminum alloys.

Cutting + machining
The first step in metal processing is cutting, which is simply cutting the raw material or separating it according to its shape to obtain a blank. Common metal cutting methods include: abrasive cutting, saw cutting, flame cutting, plasma cutting, laser cutting and water jet cutting.

laser processing
Abrasive cutting
Use a high-speed rotating grinding wheel to cut steel. It is a relatively common cutting method. The grinding wheel cutting machine is light, flexible, simple and convenient to use, and is widely used in various occasions, especially on construction sites and interior decoration. It is mainly used to cut off some small diameter square tubes, round tubes, special-shaped tubes, etc.

saw cutting
The method of cutting a workpiece or material into slits with a saw blade is called sawing. Sawing is performed using a metal band saw. Cutting materials is the most basic need for metal processing, so sawing machines are standard equipment in the machining industry. The process of using a saw requires selecting the appropriate saw blade according to the hardness of the material and adjusting the optimal sawing speed.

Flame cutting (gas cutting)
The process of flame cutting uses a chemical reaction between oxygen and hot steel to heat the metal, softening and eventually melting it. Acetylene or natural gas is often used as heating gas.

Flame cutting can only cut carbon plates and is not suitable for other types of metals, such as stainless steel or copper and aluminum.

The advantage of flame cutting is low cost and the maximum cutting thickness can reach two meters. The disadvantages are that the heat-affected zone and thermal deformation are relatively large, and the cross-section is rough and contains a lot of slag. Considering the subsequent processing, more allowance should be made.

plasma cutting
The plasma cutting method was invented in the 1950s. It is a processing method that uses the heat of a high-temperature plasma arc to partially melt (and evaporate) the metal at the incision of the workpiece, and uses the momentum of the high-speed plasma to remove the molten metal to form the incision.

laser cutting
Laser cutting uses a high-energy laser beam to heat, locally melt, and vaporize metal to complete the cutting of the material. It is usually used for efficient and precise cutting of thin steel plates (<30mm).

The cutting quality of laser is very excellent. Not only is the cutting speed fast, but the dimensional accuracy is also very high (up to ±0.05mm). Moreover, because the laser beam acts on a very small area, the heat affected zone is very small and the workpiece is almost not deformed.

waterjet cutting

Waterjet cutting is a processing method that uses high-pressure water flow to cut metal. As technology continues to improve, abrasives such as garnet sand and emery are also mixed into high-pressure water to assist cutting to increase the cutting speed and cutting thickness (up to 200mm). The accuracy of waterjet cutting can reach ±0.4mm or higher.

sheet metal
Sheet metal is a comprehensive cold processing process for metal sheets (usually less than 6mm), including shearing, punching/cutting/compositing, folding, riveting, splicing, forming (such as automobile bodies), etc. Its distinctive feature is that the thickness of the same part is consistent. There are two main methods of surface treatment of sheet metal: plastic spraying (powder spraying) and oil spraying. Large parts are usually sprayed with plastic, while small parts can be sprayed with oil.

Sheet metal processing and cutting technology has the advantages of high speed, high precision and high adaptability, thin cutting seam, small heat affected zone (small deformation), good cutting end face quality, noiseless cutting, and weld seam grouping and performance close to the base material. ; Moreover, the processing requires only simple fixtures and no molds, which can replace the processing method of punching with complex molds, which can greatly shorten the production cycle and reduce production costs.

3D printing
Currently, metal 3D printing all uses SLS technology, which requires the use of laser to solidify the material into a whole. The difference is that the SLS process uses an infrared laser beam, and the material is made of powder of metal or its composite. First, a very thin layer (sub-millimeter level) of raw material powder is spread on the workbench, and then the laser beam under computer control passes through the 3D scanner at a certain speed and energy density to scan the layered two-dimensional data. The powder that has been scanned by the laser is sintered into a solid layer of a certain thickness, and the unscanned areas remain in a loose powder state.

1) High accuracy. At present, the accuracy of metal 3D printing equipment can basically be controlled below 0.05mm.

2) The cycle is short. Metal 3D printing does not require a mold production process, which greatly shortens the production time of the model. Generally, a model can be printed in a few hours or even dozens of minutes.

3) Personalization can be achieved. Metal 3D printing has no limit on the number of printed models. Whether one or multiple models can be produced at the same cost.

4) Diversity of materials. A metal 3D printing system can often print different materials, and the diversity of this material can meet the needs of different fields.

5) The cost is relatively low. Although metal 3D printing systems and 3D printed metal materials are relatively expensive now, if they are used to make personalized products, their production costs are relatively low.