Investment Casting

What is Investment Casting (Precision Casting)?

In investment casting, a wax or suitable polymer pattern is coated by dipping into the refractory material slurry. Once the refractory material coating is hardened then this dipping process is repeated several times to increase the coating thickness and its strength. Once the final coating is hardened the wax is melted out and molten metal is poured into the cavity created by the wax pattern. Once the metal solidifies within the mould, metal casting is removed by breaking the refractory mould.

Investment casting, also known as lost wax casting, including wax pressure, wax repair, group tree, dip slurry, wax melting, casting metal liquid and post-processing process. Lost wax casting is made of wax to cast parts with wax, wax and then coated with mud, which is mud. Mud dry, add hot water in internal wax melting. The melting end clay mold wax removal and roasting into ceramic mold. Roast at once. When the general mold is made, the sprue is left, and then molten metal is poured from the sprue. After cooling, the required parts are made.

Investment casting requires a little or no addition cutting, also known as the lost wax casting in the past, the parts made by investment castings are accuracy in dimensional and surface quality are better than other casting method. In addition, it can be used for some high complexity, not easy processing casting parts.

Investment Casting Process

As shown in image, Investment casting process can be summarised in following steps – Master pattern making, Master die manufacture, Pattern making, Pattern assembly, refractory mould making, dewaxing, casting, and part removal.

Investment casting known as the lost wax casting is a precision casting process as it is capable of making high accuracy and intricately detailed castings compared to similar manufacturing processes such as sand casting.

Typical parts include turbine rotors, gears, electronics enclosures, valves, jewellery and dental fixtures. Parts up to 1.5 m in diameter and weighing up to 1140 kg have been cast successfully in the past by this process, although typical part would be on average less than 100 mm in size and weighs less than 500g.

History of Investment casting

Although Investment casting has been used in various forms since it was first used by ancient Egyptians between 4000 and 3000 B.C, it was only after the World War II its industrial importance and popularity grew due to the growing demand for parts in aircraft engine and airframe sector.

Investment casting has changed from the days where clay was packed around the bee’s wax pattern to use of ceramics shell and the introduction of special dewaxing ovens etc.

The high manufacturing cost of master dies has traditionally limited investment casting to large production quantities, but the introduction of additive manufacturing or 3D printing of wax patterns in recent years has eliminated the manufacturing cost of dies and enable the use for shorter runs.

Investment Casting Advantages

Investment Casting Quality

We are professional casting parts manufacturer & factory in Ningbo, China, where is famous for casting items as a production Zone. We have been offer precision Investment casting service to foreign customer for many year and enjoy good business relation with our customer.

Quality Control Policy

FHND is committed to provide high quality components with competitive price. Each part will be strickly machined to the print.
FHND is committed continually improves the effectiveness of the quality management system (QMS) and sets quality objectives and continuous improvement plans.
FHND is committed introducing all staff to its quality policy and quality systems,to familiarize themselves with the QMS and strive to continue to improve upon the quality, capability and work environment.

Material Supply

To be sure material specification and size correct.
To be sure material chemical composition correct, material certification must be provided in each material purchasing lot.

Equipment Maintain

Machining equipments maintain: Checked by each day, have records to track.
Inspection equipment maintain: Checked by each 15 days, have records to track.

Machining Process

Setup work instruction chart for each part.
Check production process and updated drawing issue before machining.
Fixed Inspection: 4 times/shift, have records to check, carried by QC.
Random Inspection: to avoid uncertain potential quality issues.
Final Inspection: Each part have its final inspection standard before packing, have inspection sheet to track.

Packing and Assembly

To meet custom requirment, including labels, cartons, pallets etc before shipment.