What Is Investment Casting？
What Is Investment Casting？Investment casting is a casting method in which a pattern is made of fusible materials, and after molding, the pattern is melted and discharged out of the mold, so as to obtain a cavity without parting surface, and a casting method is obtained after pouring.
investment casting process
The main processes include wax mold making, shell making, lost wax, roasting and pouring.
- 1) Wax mold manufacturing – press the wax melted into a paste into the mold, and take it out after condensation to obtain a wax mold.
- 2) Manufacture of the mold shell – immerse the wax mold or wax module into the coating slurry made of water glass and quartz powder, so that the coating evenly covers the surface of the wax mold, and then evenly sprinkle a layer of fine quartz sand on it, and then Put the hardener in ammonium chloride solution to harden the crust.
- 3) Melt and remove wax mold – immerse the mold shell covered with wax mold in hot water at 85-95 ℃, so that the wax material is melted and removed from the mold shell, thereby leaving a cavity in the mold shell.
- 4) Roasting – the shell must be roasted at 800-950 ℃ before pouring, the purpose is to remove the moisture, residual wax and other impurities in the shell and clean the cavity.
- 5) Pouring – In order to improve the filling ability of the alloy and prevent defects such as insufficient pouring and cold isolation, it is usually poured while it is hot (600-700°C) immediately after firing.
China Investment Casting Company – China Lost Wax Casting Manufacturer
BE-CU Rapid Prototyping Company(Pintejin Group – Website:Be-cu.com) Specializing in the manufacturing of lost wax investment castings and machined parts in carbon steel and alloy steel, our company is a large-scale professional investment casting foundry with powerful machining capabilities in China. It consists of 2 major facilities, both steel casting foundry and CNC machining factory which enable us to supply precision casting parts with annual capacity of over 20,000 tons, and the products are mainly exported to Europe, America, Japan and other destinations around the world.
Our company was established in 1995, it covers a total area of about 40,000 square meters and has about 500 employees. The headquartersis located in the famous industrial town humen, Dongguan in China.The investment casting foundry is equipped with several types of energy-saving & environmentally-friendly production lines including automatic or semi-automatic production lines of key processes: wax making, shell making, pouring, heat treatment. The machining factory is located in headquarters and is fully equipped with complete and advanced CNC machining equipment including 30 vertical and horizontal machining centers, and more than 70 CNC machines and 50 other machining equipments., the machining facility is fully independent from the casting foundry and has an independent management team and tailored business model to suit. In addition to the casting, forging and machining, it also has the facility to machine various profiles. Our company also has a lot of advanced inspection equipment, including Spectrometer, Metallographic Microscope, Tension Tester, Low Temperature Tester, X-ray Tester, MPT, UT, CMM, Video Measurement Machine and so on. With these advanced facilities & instruments, we are able to supply the high quality castings to our customers, and make products meeting comprehensive inspection requirements on chemical composition, mechanical properties, non-destructive testing and high precise dimensional inspections.
Our products cover a wide range of industries including train & railway, automobile & truck, construction machinery, mining machinery, forklift, agricultural machinery, shipbuilding, petroleum machinery, construction, valve and pumps, electric machine ,hardware, power equipment and so on. We are capable to produce products according to customers’ drawings or samples, we focus on both carbon steel and alloy steel. Up to today, more than 100 raw materials and 5,000 kinds of different products have been developed and produced by us. We are familiar with the material standards of many countries, such as Chinese GB, American ASTM, AISI , German DIN, European EN, Japanese JIS, British BS, Australian AS and Association of American Railroads (AAR ) and other industrial standards.
Given that traditional foundries only rough machining, our company has completed a transformation and upgraded to a deep-processing manufacturer with expanded production capabilities. Our core values are providing our customers with perfect overall solutions, great finished products and excellent customer service, and strives to increase products’ added value for its core competitiveness. We focus on developing high-quality products for top-end markets, our products are not only for domestic customers, but exported to over 30 countries such as USA, Germany, Japan, Spain, Italy, UK, France, Holland, Australia and etc. Our clients include many OEM customers who specialize in railway, automobile and construction machinery, we already have had cooperation with some the world’s Top 500 companies as one of their major steel casting suppliers in China.
Our china investment casting company has carried out an information-based management which is driven by an ERP system and we are making efforts to standardize our management system. We are both ISO9001 and TS16949 certified, and currently integrating some other advanced management modes in our system as well, such as 5S, performance management, lean production manufacturing etc. In addition, we have established the ISO14001 environmental management system in order to gain a win-win situation for the enterprise’s performance and social benefits from the long term perspective.
The company has set its strategic objective which is “Leading development in this industry, striving to provide a casting enterprise with core competitiveness and core value”, confirmed with its core competitiveness that “Leading Ideas, Advanced Equipments, Excellent QC, and Perfect Services”. It sticks to the quality management philosophy that “Starting from the customer needs and ending with their satisfaction, focusing on customer demands and exceeding their expectations”. With the enterprise spirit of “Moving with the times, pioneering and innovating, harmony and win-win, striving for excellence”, and based on the working-style of “Honesty and Practicality, Persevering Unremittingly, Teamwork Spirit,Achieving Greatness”, our company would like to sincerely invite the global prospective buyers to pay a visit and have a good cooperation for a splendid future together.
Features Of Investment Casting
- It can cast all kinds of complex castings, especially high-temperature alloy castings, such as jet engine blades with their streamlined outline and cooling cavity, which can hardly be formed by mechanical processing. Mass production can be achieved, the consistency of castings is ensured, and the stress concentration of residual knife lines after machining is avoided.
- The dimensional accuracy of investment castings is relatively high; generally, it can reach CT4-6. Of course, due to the complex process of investment casting, there are many factors that affect the dimensional accuracy of castings, such as shrinkage of mold materials, deformation of investment casting molds, and the presence of mold shells. Due to the change of the star in the process of heating and cooling, the shrinkage rate of the alloy and the deformation of the casting during the solidification process, although the dimensional accuracy of the ordinary investment casting is high, its consistency still needs to be improved.
- When pressing the investment mold, the mold with high surface finish of the cavity is used. Therefore, the surface finish of the investment mold is also relatively high. In addition, the mold shell is made of a special high-temperature-resistant binder and a refractory coating made of refractory materials. The surface finish of the cavity in direct contact with the molten metal is high, so the surface finish of the investment casting is higher than that of the general casting, generally reaching Ra.1.3.2um.
- The biggest advantage of investment casting is that because the investment casting has high dimensional accuracy and surface finish, it can reduce the machining work, just leave a little machining allowance on the parts with higher requirements, even some Some castings only leave grinding and polishing allowance without machining.It can be used. It can be seen that the use of investment casting china method can save a lot of machine tool equipment and processing time, and greatly save metal raw materials.
What Is An Investment Casting Material?
The materials used to make the shell can be divided into two types, one is used to directly form the shell, such as refractory materials, binders, etc.; the other is used to obtain high-quality shells, simplify operations and improve processes. materials, such as fluxes, hardeners, surfactants, etc.
The refractory materials used in investment casting are mainly quartz and corundum, as well as aluminum silicate refractories, such as refractory clay, bauxite, coke gemstone, etc. Sometimes zircon, magnesia (MgO), etc. are also used.
The most common binder used in lost wax casting is silicic acid colloid solution (referred to as silicic acid sol), such as ethyl silicate hydrolyzate, water glass and silica sol. The substances that compose them are mainly silicic acid (H2SiO3) and solvents, and sometimes stabilizers, such as NaOH in silica sol.
Ethyl silicate hydrolyzate is the earliest and most common binder used in silicic acid sol mold casting obtained by hydrolysis of ethyl silicate; the water glass shell is easily deformed and cracked, and the dimensional accuracy and Surface finish is poor. However, in our country, when the production precision requires carbon steel castings and non-ferrous alloy castings with a lower melting point, water glass is still widely used in production; silica sol has good stability and can be stored for a long time. Special hardener, but the wetting of the investment mold by silica sol is slightly poor, and the shell hardening process is a drying process, which takes a long time.