Die casting is the process of forcing molten metal under pressure into metal molds or dies. It is one of the most economical and effective methods of producing moderate to high-volume quantities of parts. There are three main requirements for producing commercially acceptable die castings. They are:
- An efficient casting machine
- Well designed and well constructed die
- Suitable casting alloy
The equipment needed to produce Aluminium die casting are essentially the molds and a die casting machine that holds, opens and closes the molds or dies. The variables that determine the surface quality and consistency of the part are directly related to the die itself. The die must possess the quality of thermal balance (heat input vs. heat extraction) this controls surface quality, soundness of the part and dictates cycling speed. The three main variables that affect the quality of the part are:
- Die design
- Die material
- Die production method
At CL TECH, a aluminum die casting china company, we promise to provide you with die cast parts of the highest quality and at the best value. We can produce aluminum die cast parts with weights from 20g to 10kgs, and with a length up to 800mm. We inject the metal into the mold under high pressures of 10-210Mpa (1,450-30,500 psi). This results in a more uniform part with a good surface finish and good dimensional accuracy, (0.2% of casting dimensions). Post machining can be totally eliminated for most parts and in other cases only light macining is required to bring dimensions to the proper size. We use aluminum material of ASTM grade 380, 390, and aluminum alloy die-casting (ADC12 and ADC14). We can produce parts such as automotive engine house covers, light covers, various housing assemblies and more.
Die casting standard
- Positive Metal – Due to the nature of the investment aluminum casting process, random positives are encountered and these vary by alloy and part configuration. Unless otherwise agreed, these will be limited to a size of 0.015-0.030″ high by 0.125″ by 0.125″ and no more than one per 1″ square. Smaller defects of all sizes may be present at random but not in places where they interfere with the function of the part – such as holes, knurls, or lettering. Positive metal requirements other than this will be specified by the customer at time of quotation.
- Surface Pits – Random negatives may also occur. These will be limited to 0.030-0.060″ by 0.030″ deep in size, no more than one of those per 1″ square. Unless otherwise specified by the customer, smaller negatives may be present, providing they do not interfere with the function of the part.
- Nonfill – Edges may be rounded up to 0.015″ radius even though tooled sharp. Sharper or more rounded edges can be provided as agreed between purchaser and foundry.
- Cleanliness – Aluminum die Castings will be sand, grit or shot blasted to remove casting and heat treatment scale or other foreign material. Stainless steel castings will not be pickeled or passivated unless specified. Castings will be provided with sand blasted, grit blasted or vibropolished surfaces and be of uniform appearance typical of those processes. Unless the purchaser specifies a rust preventive treatment, some light rusting may be present.
- Linear Indications – Parts will contain no linear cold shuts, visual cracks, or visual shrinkage, except as agreed with customer.
- Surface Texture – The surface texture standards for investment casting will be 125 RMS maximum.
- Soundness
- The foundry will establish a casting method that is capable of producing castings that show less than 10% shrinkage porosity in any cross section area. Shrinkage will not be present in an area where subsequent machining will reveal it as a visual surface defect.
- Internal Defects
- Some limited quantity of internal defects, including gas holes, slag entrapment, non-metallic inclusions, or porosity may be encountered by the purchaser. If these render the casting unusable, methods of inspection and acceptance limits to exclude such defects will be established by the purchaser and the foundry prior to further production of the die casting.
- Note:
- This is not, or intended to be an all-inclusive specification, but is meant more as a guideline. Any quality conditions or inspection criteria not addressed here or that are beyond the tolerances or specifications listed here can be negotiated in the purchase agreement.
Aluminum die casting
Aluminium is type of metal that is being used extensively in various disciplines and industries. In any setting you cannot miss finding at least item made of aluminum. Despite being used to make various parts, aluminum is being used in the construction industry to fit glasses. Due to the high demand for aluminum, there are numerous companies that deal with aluminium die casting which involves pouring molten metal into molds with different patterns that resemble the shape of the final product part, An aluminum casting China company CNM tech is well known for its advance technology in for die casting, magnesium die casting and zinc die casting service.
Properties of aluminum
Aluminum is very light weight metal with low density, but its density does not affect the strength of the metal. However, the strength is inversely proportional to temperature, at high temperature, the strength decreased and at low temperature it increase. The metal is not magnetic unlike other metals like steel.
Method of aluminum casting
There are three commonly used methods of casting aluminum
1, die casting method
This method is commonly used in the mass production of aluminum casting parts and uses pressure to put the molten aluminium material into a die casting mold made of steel. The dies have different shape depending on the shape of final production which designed by the customers purpose.
2,sand casting method
This uses fine texture sane compacted in a pattern with the shape and large than the size of final product as it shrinks during cooling. The pattern has channels where the molten metal is poured and when the metal solidifies the sane is broken and removed leaving the aluminum part behind. This method is very economical and can be used for mass production of aluminum parts as the sane can be reused
2, Permanent mold casting method
This method uses other metals commonly steel to make die casting molds, it is suitable for massive production of aluminum casting that are similar thus require consistency. It highly recommended in making mechanical parts that are well known for durability.
In today, the world of companies who is looking for aluminum die casting, magnesium die casting, zinc die casting, most of them at the first idea is looking for an aluminum die casting china company, or magnesium die casting China company, buy aluminum casting from china casting company that will service you fast and low cost.
Casting of metals under pressure is a method of manufacturing castings from alloys, in which the alloy acquires the shape of a casting, quickly filling the mold under high pressure. This method is used for alloys of non-ferrous metals (based on zinc, aluminum, copper, magnesium, tin-lead alloy) because of their low melting point, and for some steels. The resulting products can be from tens of grams to tens of kilograms. we called this process as high pressure die casting process
The main advantages of aluminium die casting under pressure are high productivity, minimal need for machining the product, and the fact that the blanks obtained in this way have a high surface quality.
Die-casting of aluminum under pressure is widely used for medium-series, large-scale or mass production of castings. The method of casting aluminum under pressure is widely used in the field of automobile and aircraft building, electrical engineering, instrument making, etc.
The main advantages of the pressure die casting method
- Productivity and economy.
The classical casting of aluminum alloys under pressure is still the most productive and the most economical. Therefore, aluminum in the form of castings under pressure still has the largest share among processed metals.
- Aluminum remains promising.
Industry, especially automotive, requires more and more light parts. Due to this and the above reasons, aluminum remains an indispensable material. The raw materials, bauxites, are available in large quantities. This gives us confidence that we will be able to innovate for a long time and work with aluminum for the future.
- Aluminum is relatively easy to melt.
- Metal is recycled – an important advantage in terms of environmental protection.
Another known casting method is zinc die casting. Technically pure zinc has satisfactory mechanical properties, it is well suited for rolling,
pressing, drawing and stamping in the cold state and in the temperature range 130 -170 degree. Zinc has a high density in the solid and liquid state, low melting and boiling temperature, linear shrinkage. They produce several brands of zinc, which differ in the quantity of impurities.
The main applications of zinc die-casting under pressure are the production of door fittings, carburetor cases, pumps, decorative elements, as well as the font-making industry. The parts made of zinc have a high density and well repeat the relief of the mold, therefore it is possible to make castings from them with already printed pattern and very small details.
Magnesium Die casting under pressure. The guaranteed availability and the combination of the positive properties of high purity magnesium alloys make the lightest metal structural material attractive for use in many industries, for example:
- Lightweight parts for the automotive industry.
- Cases for office machines, laptops, mobile phones and speakers.
- Machines for domestic work, etc.
Properties and advantages of the method.
- Due to very good fluidity, it is possible to produce even finer-walled or more complex parts than with aluminum die casting.
- New applications in the electrical industry due to good thermal conductivity, as well as electromagnetic shielding of the metal.
- Compared with plastics, greater strength and better thermal conductivity are achieved.
- Magnesium reserves are practically inexhaustible.
- Negotiable material is processed secondarily.
- High-purity magnesium alloys are less susceptible to corrosion.
- Good sound insulation properties from noise.
- Weight reduction of approximately 30% compared to aluminum.
Die casting is one of the most advanced methods of mass production of castings.
Along with such advantages, injection molding has a number of disadvantages.
1) High cost of basic equipment and molds;
2) Formation of porosity and shells in massive sections of castings, in connection with which the strength and tightness are reduced, thermal treatment of castings, is excluded;
3) It is possible to fill only aluminum, magnesium, zinc and copper alloys ( brass die casting ), but not all fusible alloys, even aluminum, can be used for injection molding.
The economic feasibility of casting in one way or another, except for the technological design of the construction of the part, is determined by the laboriousness of manufacture and the technological possibility of making castings. The high cost of tooling equipment leads to the fact that the manufacture of castings by injection molding is economically feasible when ordering more than 20,000 pieces. With smaller orders advisable other methods.