Die Casting’s Blog

Modeling is based on making core casting process requirements in determining a good method of modeling, ready to shape the material basis. Casting the accuracy of all of the production process and the economic effects will depend mainly on this procedure. In many modern casting workshop, modeling-made batteries have achieved a mechanized or automated. Sand commonly used form core-making equipment is high, medium and low pressure molding machine and threw sand machine, without me radio pressure molding machine, radio-core, cold and hot-box machines.

Since the casting mold in cooling pouring out after a gate, riser and metal spikes Phi slit, sand casting of the casting also adhesion of the sand, it must be clean-up process. Such devices are the work of the Blasting machine, gate riser cutting machines. Sand-casting sand clean-up is a poor working conditions processes, in the choice of modeling methods, should be taken into account for as much as possible with sand to create convenient conditions for clean-up. Casting a result of some special requirements, but also by casting post-processing, such as heat treatment, plastic surgery, anti-rust treatment, such as rough.

Casting is more economic methods of rough shape, the shape of more complex components demonstrated its economy. aluminum die casting Such as car engine block and cylinder head, ship propellers and exquisite works of art, and so on. Cutting some of the difficult parts, such as the combustion turbine parts do not have to nickel-based alloys casting method can not be forming.

In addition, the die casting of parts of the size and weight to a wide range of metal types of almost unlimited; parts in a general mechanical properties, it is also a wear and corrosion-resistant, shock-absorbing properties, and so is the other metal forming methods such as forging , Rolling, welding, salt, and so can not. Therefore, in casting machine manufacturing methods used in the production of rough parts, and the number is still on the tonnage is the largest.

Casting often use a variety of metal materials, coke, wood, plastic, gas and liquid fuels, such as modeling materials. Have the necessary equipment used in various metal smelting furnace, a Mixer with the various Mixer, a shape-made batteries used in various molding machine, machine-made batteries, cleaning up the castings used for loading sand, Shot Blasting Machine And so on. Casting is also available for special machinery and equipment, and many transportation and material handling equipment.

Casting and other technology have different characteristics, mainly wide adaptability, needed materials and equipment, pollution of the environment. Casting will have dust and harmful gases and noise pollution to the environment, compared to other machinery manufacturing processes to become more serious, need to take measures to control.

Casting product development requirements of the trend is casting a better overall performance, higher accuracy and less headroom and clean the surface. In addition, the requirements of energy-saving society and restore the natural environment of the call also getting higher and higher. To meet these requirements, the new cast alloy will be developed, the new smelting technology and new equipment will be corresponding.

Casting the mechanized production continuously improve the degree of automation in the same time, to be more flexible production development, to expand the volume and variety of different production adaptability. Conserve energy and raw materials of new technologies will be giving priority to the development, have little or no pollution of the new equipment, new technology will be the first attention. Quality control technology in all stages of testing and nondestructive testing, stress determination, there will be a new development

ruyi iron casting Foundry employees conduct quality control tests from the start of the production process to the completion of the casting process.

Sand Lab
Before we use green sand for mold development, we test it in our sand lab for strength characteristics and compactability from the start.

Metals Lab
We conduct a variety of tests in our Metals lab during production and the testing results are then reported to our Gray Iron Casting customers.

Metals lab testing services we provide include:

Evaluating the molecular structure of a casting section using a Unitron MEC 8484 stereomicroscope.
Evaluating the thickness of casting walls by measuring and verifying the thickness using a Kraut-Kramer DML-4 ultrasonic thickness gauge.
Verifying the tensile strength of the casting using a Detroit tensile strength test machine to perform mechanical performance tests.
Verify the chemical composition of the die casting using spectrometer.
Shop Floor
ruyi Foundry personnel conduct a number of tests on the shop floor during production and the testing results are then reported to our Gray Iron casting customers.

Shop floor testing services include:

Hardness testing using a Tinius Olsen Brinell variable load hardness test machine,
Pyrometric testing using an Ircon optical pyrometer located at the Disamatic molding machine to measure and verify the temperature of the molten Gray Iron being cast, and
Mold hardness testing using a Dietert Mold hardness tester to ensure the molds have hardened enough to accept the molten Gray Iron and not deform.

A few days ago, from a relevant department was informed that: Jinnan District Dazhan Valve Plant, and other seven companies were the Ministry of Agriculture, the Global Environment Facility, the United Nations Development Programme and United Nations Industrial Development Organization has granted "township enterprises in China energy-saving and greenhouse gas emission reduction projects" Show business title. Energy conservation and the implementation of emission reduction projects show, to effectively promote the work of local energy-saving technical transformation of emission reduction, promote the sustainable development of enterprises. The industrial outskirts of the city began a comprehensive energy-saving emission reduction battle.

It is understood that the Global Environment Fund, China’s Ministry of die casitng Agriculture, the United Nations Development Programme and United Nations Industrial Development Organization in China jointly organized the implementation of the "Chinese township enterprises in energy conservation and greenhouse gas emission reduction projects." Jinnan District 7 are casting processes of industrial enterprises included in the "Chinese township enterprises in energy conservation and greenhouse gas emission reduction projects" plan. 7 companies were received 10,000 U.S. dollars to support the project funds and the Central Government to give 50,000 yuan of funds energy-saving technological transformation, energy-saving technological transformation of the emission reduction achieved remarkable results. 7 Biaomei enterprises, saving 850 tons, more than 2,100 tons of carbon dioxide emission reduction, the average corporate rate of 16.7 percent energy saving, technological transformation before and after the rejection rate decreased 3.4 percent.

2008, the city will be more deeply implement the provisions relating to the work of energy conservation, energy-saving emission reduction as the promotion of scientific development of Kit, promote industrial development in rural areas and construction of the organic unity of ecological civilization, lay a good energy-saving emission reduction battle, protracted war, to speed up Formed to conserve energy resources and protect the ecological environment of the industrial structure and the mode of growth, consumption patterns.

Bar grating is designed to for many applications. Bar grating casting is a strong choice for projects ranging from trenches to decking. Aluminum bar grating is a good choice when a lightweight, corrosion resistant material is desired. Choose from many options such as: flush top, rectangular bar, plank, and I-bar. Aluminum grating is available in the swage locked, pressure locked (dove tail) and riveted design. Carbon steel bar grating is a nice choice when your project requires a strong material and you are not going to expose the grating to an expressly corrosive environment. Choose from plain or serrated surfaces, galvanized or standard black, and light or heavy duty grating. Stainless steel bar grating provides a superior corrosive & oxidation resistant material in a material stronger than aluminum. Stair tread bar grating is typically offered in a welded construction and is made with a checkered plate nosing that is welded to the leading edge of the tread.

Gravity Cast Parts
1) Materials: aluminum, brass. 2) Applied software for specification drawings: Pro-E, Auto CAD 2000. 3) die casting Main equipment: vertical type casting machine, horizontal type casting machine, rock over. 4) Applications: auto parts, machine parts, plumbing products

Sand casting is one of the most popular and simplest types of casting that has been used for centuries. Sand casting allows for smaller batches to be made compared to permanent mold casting and at a very reasonable cost. Not only does this method allow manufacturers to create products at a low cost, but there are other benefits to sand casting, such as very small size operations. From castings that fit in the palm of your hand to train beds (one casting can create the entire bed for one rail car). Sand casting also allows most metals to be cast depending on the type of sand used for the molds.

Sand casting requires a lead time of days for production at high output rates (1-20 pieces/hr-mold) and is unsurpassed for large-part production. Green (moist) sand has almost no part weight limit, whereas dry sand has a practical part mass limit of 2300-2700 kg. Minimum part weight ranges from 0.075-0.1 kg. The sand is bonded together using clays (as in green sand) or chemical binders, or polymerized oils (such as motor oil). Sand can be recycled many times in most operations and requires little additional input.

Bar grating is designed to for many applications. Bar grating is a strong choice for projects ranging from trenches to decking. Aluminum bar grating is a good choice when a lightweight, corrosion resistant material is desired. Choose from many options such as: flush top, rectangular bar, plank, and I-bar. Aluminum grating is available in the swage locked, pressure locked (dove tail) and riveted design. Carbon steel bar grating is a nice choice when your project requires a strong material and you are not going to expose the grating to an expressly corrosive environment. Choose from plain or serrated surfaces, galvanized or standard black, and light or heavy duty grating. Stainless steel bar grating provides a superior corrosive & oxidation resistant material in a material stronger than aluminum. Stair tread bar grating is typically offered in a welded construction and is made with a checkered plate nosing that is welded to the leading edge of the tread.

Gravity Cast Parts1) Materials: aluminum die casting brass. 2) Applied software for specification drawings: Pro-E, Auto CAD 2000. 3) Main equipment: vertical type die casting machine, horizontal type casting machine, rock over. 4) Applications: auto parts, machine parts, plumbing products

Plaster casting is similar to sand molding except that plaster is substituted for sand. Plaster compound is actually composed of 70-80% gypsum and 20-30% strengthener and water. Generally, the form takes less than a week to prepare, after which a production rate of 1-10 units/hr-mold is achieved, with items as massive as 45 kg and as small as 30 g with very high surface resolution and fine tolerances. Parts that are typically made by plaster casting are lock components, gears, valves, fittings, tooling, and ornaments.Plaster casting is an inexpensive alternative to other molding processes due to the low cost of the plaster and the mold production. It may be disadvantageous, however, because the mold quality is dependent on several factors, “including consistency of the plaster molding composition, mold pouring procedures, and plaster curing techniques.”[4] If these factors are not closely monitored, the mold can result in distorted dimensions, shrinking upon drying and poor mold surfaces.

Once used and cracked away, normal plaster cannot easily be recast. Plaster casting is normally used for non-ferrous metals such as aluminium-, zinc-, or copper-based alloys. It cannot be used to cast ferrous material because sulfur in gypsum slowly reacts with iron. The plaster itself cannot stand temperatures above 1200oC, which also limits the materials to be cast in plaster. Prior to mold preparation the pattern is sprayed with a thin film of parting compound to prevent the mold from sticking to the pattern. The unit is shaken, so plaster fills the small cavities around the pattern. The plaster sets, usually in about 15 minutes, and the pattern is removed. The plaster is dried at temperatures between 120o and 260oC. The mold is preheated and the molten metal poured in.

Plaster casting represents a step up in sophistication and requires skill. The automatic functions are easily handed over to robots, yet the higher-precision pattern designs required demand even higher levels of direct human assistance.

Aluminum Die Casting leverages our experience in aluminum die castings, precision machining, assembly and program management philosophy in providing our customers with industry leading solutions.

Automation

Die Cast, with our commitment to continuous improvement, is currently 85% automated and will be 89% automated by the end of 2005. We continue to implement process automation enhancements.

Aluminum Die Casting Rimrock automation equipment:

Auto Ladle
Auto Spray
Auto Extract
Shot Monitoring
Automatic plunger lube application
Trim unloading

Process and work flow improvements including:

Special machines for high volume repetitive products.
Dedicated Work cells.
Cellular automation.
Trim stations/secondary operations at die cast machines.
Packaging at trim stations.
Part Conveying Systems.
Automation offers:

Improved quality through consistent processing.
Better equipment utilization.
Higher productivity with reduced labor.
Cleaner work environment.
Improved Morale.

Die-casting is similar to Permanent mold castings except that the metal is injected into the mold under high pressure of 10-210Mpa (1,450-30,500) psi . This results in a more uniform part, generally good surface finish and good dimensional accuracy, as good as 0.2 % of casting dimension. For many parts, post-machining can be totally eliminated, or very light machining may be required to bring dimensions to size.

Die-casting can be done using a cold chamber or   hot chamber process

1.In a cold chamber process, the molten metal is ladled into the cold chamber for each shot. There is less time exposure of the melt to the plunger walls or the plunger. This is particularly useful for metals such as Aluminum, and Copper (and its alloys) that alloy easily with Iron at the higher temperatures.

2.In a hot chamber process the pressure chamber is connected to the die cavity is immersed permanently in the molten metal. The inlet port of the pressurizing cylinder is uncovered as the plunger moves to the open (unpressurized) position. This allows a new charge of molten metal to fill the cavity and thus can fill the cavity faster than the cold chamber process. The hot chamber process is used for metals of low melting point and high fluidity such as tin, zinc, and lead that tend not to alloy easily with steel at their melt temperatures.

Die casting molds (called dies in the industry) tend to be expensive as they are made from hardened steel-also the cycle time for building these tend to be long. Also the stronger and harder metals such as iron and steel cannot be die-cast

Common Alloys in Die Casting

Aluminum, Zinc and Copper alloys are the materials predominantly used in die-casting. On the other hand, pure Aluminum is rarely cast due to high shrinkage, and susceptibility to hot cracking. It is alloyed with Silicon, which increases melt fluidity, reduces machinability. Copper is another alloying element, which increases hardness, reduces ductility, and reduces corrosion resistance.

Aluminum is cast at a temperature of 650 ºC (1200 ºF). It is alloyed with Silicon 9% and Copper about 3.5% to form the Aluminum Association 380 alloy (UNS A03800). Silicon increases the melt fluidity, reduces machinability, Copper increases hardness and reduces the ductility. By greatly reducing the amount of Copper (less than 0.6%) the chemical resistance is improved; thus, AA 360 (UNS A03600) is formulated for use in marine environments. A high silicon alloy is used in automotive engines for cylinder castings, AA 390 (UNS A03900) with 17% Silicon for high wear resistance. Common aluminum alloys for die casting are summarized as follows:

Zinc can be made to close tolerances and with thinner walls than Aluminum die casting, due to its high melt fluidity. Zinc is alloyed with Aluminum (4%), which adds strength and hardness. The casting is done at a fairly low temperature of 425 ºC (800 ºF) so the part does not have to cool much before it can be ejected from the die. This, in combination with the fact that Zinc can be run using a hot chamber process allows for a fast fill, fast cooling (and ejection) and a short cycle time. Zinc alloys are used in making precision parts such as sprockets, gears, and connector housings.

Copper alloys are used in plumbing, electrical and marine applications where corrosion and wear resistance is important.

Minimum wall thicknesses and minimum draft angles for die casting are :

Die-castings are typically limited from 20 kg (55 lb) max. for Magnesium, to 35 kg (77 lb) max. for Zinc. Large castings tend to have greater porosity problems, due to entrapped air, and the melt solidifying before it gets to the furthest extremities of the die-cast cavity. The porosity problem can be somewhat overcome by vacuum die casting

From a design point of view, it is best to design parts with uniform wall thicknesses and cores of simple shapes. Heavy sections cause cooling problems, trapped gases causing porosity. All corners should be radiused generously to avoid stress concentration. Draft allowance should be provided to all for releasing the parts-these are typically 0.25º to 0.75º per side depending on the material.

The component can be produced in either Aluminium or Zinc. Using a permanent mould called Gravity Die Tooling. Gravity Die-Castings are produced by molten metal entering an aperture in the Gravity Die Tooling, this aperture allows metal to enter the cavity to form the cast shape of the Gravity Die-Casting required by the customer.

Gravity Die-Casting produced in all grades of Aluminium and Zinc. Higher volumes of precision castings are achievable using the Gravity - Die Casting, external or internal is either produced by means of a purpose made steel core or as previously mentioned an Airset sand core.

Gravity Die-Castings produced are cost effective for quantities of a semi to high volumes. The finishing operations on a Gravity Die

Casting are minimal compared to a conventional sand casting, usually on a Gravity Die Casting the joint line is minimal and in some circumstances the need for an operation is not required.

Mechanical means are some times required for opening and closing of Die Tooling if the Gravity Die-Casting to be produced is large and complex.

Gravity Die-Castings if required by specification can be heat treated to adjust or improve its characteristics

Improvement to production rates of Gravity Die-Casting can be improved by the use of multiple tooling.

A Gravity Die-Tooling is able to produce Gravity Die-Castings for several years without the need of refurbishment.