CASTING FAQ GUIDE
How to Place Order about Brass and Bronze Castings?
Yide Foundry can provide accurate cost and time estimates for your custom castings.
We can produce high-quality custom metal castings that meet your requirements.
We will work with you to determine the product project, and then recommend the most economical materials and production methods.
First of all, please determine whether the product you need is suitable for our professional field according to the following factors:
Yide Foundry can use a variety of metal alloys, including ductile iron, gray cast iron, cast steel, stainless steel, mild steel and aluminum.
Custom castings will require production designs and new mould. Does your project have enough volume to rationalize customization?
Yide Foundry has our own casting factory covering an area of 20000 sqm, with over 200 employees. We provide mold designing, shell casting, sand casting, and finish machining service according to your requirements.
Yide Foundry has enough ability to manufacture clay sand casting& precoated sand casting capacity over 20,000 tons.
Request a quote
Once you have determined that Yide Foundry is a manufacturer that meets your requirements. Then, the next step is to collect the informations of the product.
Custom metal casting is a complex process. The success depends on the communication and detailed control of the entire process.
You should consider the following information in your request for quotation.
Please provide the drawings and specifications of the casting, including (but not limited to):
- Dimensions and geometry
- Acceptable dimensional tolerances
- Stress / load requirements
- Machining requirements
- Non-destructive test requirements
Please send the information to [email protected]
You can list specific metal grades, preferred materials or required properties.
Due to the inherent cost of the metal/alloy and its castability, the cost is greatly affected by the material selected.
Actual or estimated weight
Used to calculate the cost of purchasing materials, processing and transportation. Actual weight is preferred because inaccurate estimates may cause discrepancies between estimated and actual costs.
If existing mould is available, casting costs can be reduced.
If not, the design of the mould will constitute the main cost. Paying higher fees for complex mould can reduce casting costs and improve casting quality.
Include current and future expected quantities. The quantity has a great influence on production methods, tool development and total cost.
Casting surface finish (smoothness) requirements, material performance test standards and casting robustness are all key considerations for quotation.
ASTM provides the tools necessary to establish inspection standards. Most mechanical tests are performed on representative test rods.
Additional non-standard inspection requirements increase the cost of casting.
It can be expedited, but it will also increase the cost
Yide Foundry can provide secondary processing operations:
- Heat treatment
We prepare and package all products to protect them during transportation and storage.
Special requirements will increase the cost of transportation and must be notified in advance.
Through communication with our professionals, we can best understand the functions and costs of castings. Our casting experts will work with you to outline product solutions and help you realize them in the most economical way.
Is your casting information ready? Request a quote here! [email protected]
How to Choose Brass Sand Casting Foundry?
- When choosing a casting foundry, we need to figure out the following points.
First of all, we need to know the strength of the manufacturer. Generally, we can observe the manufacturer’s production ability and factory scale. At the same time, we can also learn about the reputation of the foundry from the peers or the media.
- When buying ductile cast iron parts, we cannot just look at the price, but also need to know about the product quality, service and casting technology.
In the production process of large-scale ductile castings, we generally use resin sand technology. Meanwhile, we use inspection equipment to strictly monitor the grades of ductile iron castings.Thus can improve the properties of ductile iron castings, and strengthen the product’s tensile and impact resistance is greatly.
- Zhejiang Yide Machinery Co,. Ltd. is a newborn company from Ninghai Jinma (JM)Casting Foundry, founded in 1993.
As an established company with a long history and strong professional and technical strength, Jinma has enough ability to manufacture clay sand casting & precoated sand casting capacity over 20,000 tons, with the main products: Automobile Casting, Truck Casting, Cast Iron Fire Truck, Cast Iron Toy Tractors, Forklift Parts Casting/Hand Lift Casting, Agricultural Machinery Casting, Construction Industry Casting, Brass Casting, Bronze Casting, and Heat exchangers.
Thus Yide is always committed to providing high quality but factory price customized casting services for more and more customers in the whole world.
What is Brass Casting？
Brass castings are brass moldings obtained by various casting methods. That is, putting the smelted liquid metal into a pre-prepared mold by pouring, injection, inhalation or other casting methods. Cleaning and post-processing after cooling to obtain objects with a certain shape, size and properties.
Advantages of Copper Castings
Copper castings are widely used in many fields, and have their own advantages.
The copper casting can be made from the inner cavity, and the shape is complicated. Such as various shells, CNC lathes, cylinder blocks, cylinder heads, etc.
2. Flexible processing technology and wide adaptability
The specifications of liquid molding are basically endless. The net weight can range from grams to several hundred tons; and the wall thickness can range from 0.5 mm to 1 meter. Industrial production can be dissolved into liquid metal raw materials, which can be used for liquid molding. For pig iron that is not easy to cast, liquid forming is the only way to produce billets or parts.
3. Low cost of liquid molding.
Liquid molding can be directly applied to waste and cutting, and the investment of machinery and equipment is low. In addition, the remaining amount of liquid molded parts processed is small, saving metal materials.
Classification of Brass Castings
According to different compositions, copper alloys are divided into brass and bronze.
Brass is a copper alloy with zinc as the main alloying element. According to its chemical composition, brass is divided into two types: ordinary brass and special brass.
(1) Ordinary Brass
Ordinary brass is a binary alloy of copper and zinc. Due to its good plasticity, it is suitable for the manufacture of plates, bars, wires, pipes and deep-drawn parts, such as condenser tubes, radiator tubes and mechanical and electrical parts. Brass with an average copper content of 62% and 59% can also be cast and is called cast brass.
(2) Special brass
In order to obtain higher strength, corrosion resistance and good casting performance, aluminum, silicon, manganese, lead, tin and other elements are added to the copper-zinc alloy to form special brass. Such as lead brass, tin brass, aluminum brass, silicon brass, manganese brass, etc.
- Lead brass has excellent cutting performance and good wear resistance. It is widely used in the manufacture of clock and watch parts, and the production of bearing bushes and bushes by casting.
- Tin brass has good corrosion resistance and is widely used in the manufacture of marine ship parts.
- Aluminum in aluminum brass can increase the strength and hardness of brass and improve its corrosion resistance in the atmosphere. Aluminum brass is used to make corrosion-resistant parts.
- The silicon in silicon brass can improve the mechanical properties, wear resistance and corrosion resistance of copper.
- Silicon brass is mainly used to manufacture sea-going ship parts and chemical machinery parts.
Properties of Bronze Castings
The structure of liquid metal, the formation and growth of crystal nuclei, the size, direction and morphology of grains are closely related to the solidified structure of castings. They have a significant impact on the physical and mechanical properties of castings.
The purpose of controlling the solidification structure of the casting is to obtain the desired structure.
To control the solidification structure, we must have a comprehensive understanding and in-depth study of its formation mechanism, formation process and influencing factors. At present, the established effective methods for controlling tissues include deterioration, inoculation, dynamic knotting, sequential coagulation, and rapid coagulation.
Low carbon cast bronze has good plasticity and is not easy to crack when cooled. In order to reduce the internal stress, the cast bronze parts should be tempered at high temperatures after normalizing.
For bronze castings with a carbon content of 0.35%, which are complex in structure and prone to cracks, they can only be annealed. Bronze castings should not be quenched, otherwise they will easily crack.
Bronze castings have excellent mechanical and physical properties. It can have various comprehensive properties of different strength, hardness and toughness. It can also have one or more special properties, such as wear resistance, high and low-temperature resistance and anti-corrosion, etc. The castings have a wide range of weights (from grams to 400 ton), thickness(from 0.5mm to 1m), and length (from a few millimeters to more than ten meters), which can meet different industrial sectors’ requirements.
Application of Brass Casting
Brass casting is closely related to human beings daily life. It is widely used in electrical, light industry, machinery manufacturing, construction industry, defense industry and other fields. Copper is second only to aluminum in the consumption of non-ferrous metal materials.
Electrical and electronic industries
Brass casting is most widely used in the electrical and electronic industries, accounting for more than half of the total consumption. Used in various cables and wires, motors and transformers, switches and printed circuit boards.
Machinery and transportation
In the manufacture of machinery and transportation vehicles, copper is used to manufacture industrial valves and accessories, meters, sliding bearings, molds, heat exchangers and pumps.
Cast brass is widely used in the chemical industry to manufacture vacuum vessels, distillation pots, brewing pots, etc.
In the defense industry, cast bronze is used to manufacture bullets, shells, gun parts, etc. For every 3 million bullets produced, 13-14 tons of copper are needed.
In the construction industry, brass casting is used as various pipes, pipe fittings, decorative devices, etc.
Brass and Bronze Casting Standard Grades
How To Manufacture Brass Casting?
How To Manufacture Brass Casting
The metal structure of bronze castings is looser than that of rolled bronze, and the surface is rough and porous. Besides, a few molding sand, paraffin and silicates often remain on the surface of bronze castings. If not cleaned up, it will lead to partial plating failure, so the surface cleaning and adding appropriate process steps are very important for solving the silver plating quality of bronze castings.
Generally, bronze castings follow the process as: alkaline degreasing; hot wash; cold wash; 25% hydrofluoric acid immersion; cold wash; mixed acid corrosion; cold wash; 5% alkaline solution immersion; cold wash; strike copper plating; cold wash; silver plating; cold wash; passivation; cold wash; removing film; cold wash; bright dipping; cold wash; hot wash; drying; inspection.
Due to the loose and porous metal structure of bronze castings, strict technics required in the electroplating process.
Cleaning requirements of each step to prevent the solution remaining in the pores from affecting the next step;
- The actual surface area of the bronze casting is many times larger than the calculated, and the impact current density during plating is about 3 times higher than that of general parts, thus the plating time is longer as well.
- When strike plating copper, the parts and the hanger should be shaken together frequently to ensure the uniformity of the coating color, and prevent the occurrence of mottling during silver plating that affects the appearance quality of the coating;
- When plating sliver, the tank must be charged, and the impulse current density should be electroplated for 5 minutes under the premise of shaking the workpiece, and then converted to normal current density;
- The passivation treatment after silver plating should be strengthened and washed in flowing water for 10-20 minutes, then washed with hot water, and dry immediately. The temperature of the oven should be controlled 100 ~ 150 ℃, a little longer drying time to prevent mildew.
Why Poor Quality for Bronze Casting ?
Why Poor Quality For Bronze Castings
Bronze castings have a wide application in our daily life, but there are still many people who know do not know much about bronze castings.
Agricultural machinery casting, cast machine tools, internal combustion engine castings are inseparable from bronze castings (brass casting). Here’s a peek at the close connection between bronze castings and our lives.
Factors affecting the appearance quality and internal quality of bronze castings are as below:
- There must be a rational casting process. That is, according to the structure, weight, size, characteristics of the casting alloy and the production conditions, select the appropriate parting surface and mold and core making method. Besides, rationally set the casting steel, chiller, riser and pouring system.
- The design craftsmanship of bronze castings. When designing, in addition to determining the casting geometry and size according to the working conditions and metal properties, the rationality of the design should also be considered from the perspective of casting alloys and technical properties. This means, avoid or reduce defects such as segregation, deformation and cracking of bronze casting from obvious size effects, solidification, shrinkage, stress and other problems.
- The quality of raw materials for casting. Substandard quality of metallic charge, refractory, fuel, flux, modifier, foundry sand, binder, paint and other materials will cause defects such as porosity, pinholes, slag inclusions, and sand burning, which will affect the quality of bronze castings, or even make the casting scrap when serious.
- Good casting production environment. We must formulate rational technical operation regulations, and improve the technical level of workers, so that the regulations can be correctly implemented.
Precise bronze castings can be used directly as machine parts. the use of bronze castings is also very prominent in the mechanical casting products, accounts for more than half of the weight. A majority of door handles, door locks or iron pans use bronze castings.
How to Prevent Deformation of Copper Castings?
The wall thickness of copper castings will change with shape, which is generally referred to as wrong boxes, wrong sides, or partial cores. There are many reasons for this dislocation, such as：
- Poor mold cooperation;
- Wear of positioning pin sleeves;
- Mold movement on copper castings;
- Errors in other parts of the mold or mud box;
- The sand box is not suitable;
- The clay core becomes deformed during producing, baking and transportation;
- The sand box is moved before pouring.
In order to prevent the deformation of copper castings, the following should be noted:
- On the one hand, the damage of the mold and sand box should be repaired immediately to deflect the copper casting; whether the positioning pins and positioning pins move or damage; check whether the positioning pins and pin holes on the sand box and template are worn and deformed.
- In addition, the gap between the cores must be strictly fulfilled. When forming the template, positioning pins should be used to ensure that the appearance of the copper castings of the high and low boxes are different; if required, a tenon can be used to prevent tilting.
- The deformation of copper castings is caused by casting stress, and the appearance and size of copper castings do not match the type. The reason is very complicated. The resulting temperature difference is also great. Because the beams are adjacent from top to bottom, the thickness of the beam is not only shortened due to temperature drop, but also contracted and shortened due to shrinkage and thinning. Conversely, the thin collapse reduces the collapse, resulting in a thickness collapse that is greater than the thickness collapse.
How much does brass shrink when cold?
The size of most large castings is reduced during solidification.
The percentage reduction in the size of cast iron is called casting shrinkage rate.
The shrinkage rate of tin bronze castings is 1.2%~1.4%
The shrinkage of aluminum bronze castings is around 1.6%.
Ingredients and casting temperature will have an effect on shrinkage.
A process permit test is required, in order to accurately determine the shrinkage rate.
Is Brass toxic when heated?
It mainly depends on what has changed in the copper. In essence, metallic copper is non-toxic. When copper is converted into free copper ions, it is toxic. Copper ions are heavy metals that can inactivate proteins in organisms.
Common Brass castings such as tableware, heated and used in daily life, is non-toxic.
Chronic copper poisoning is generally caused by long-term inhalation of a large amount of copper-containing gas or intake of copper-containing food. For example, workers who have been exposed to copper dust and copper smoke through the respiratory system for a long time.
What is the green stuff on my brass?
The green stuff on the surface of brass castings is the rust of copper, also known as “patina”.
“Patina” is the double salt formed by sulfur dioxide (SO2), carbon dioxide (CO2) and hydrogen sulfide (H2S) in the air, react with copper oxides on the surface of copper. Its main components are basic copper sulfate and carbonate, which are green. Patina is a dense protective film on the surface of the copper substrate.
In the long-term animal experiments on the “copper green” and other copper complex salts, it was found that they were not terribly toxic. Compared with other metals, patina is not particularly harmful.
The patina adheres closely to the copper surface,. It is insoluble in cold and hot water, and has extremely high stability.
Japanese scientists have proved that even if the patina is ground into powder and injected into the human body, the human body will not absorb it, and will excrete it through natural reactions.