Investment Casting

The investment casting process begins with a precise model (pattern) of the end product. For centuries this pattern has been made out of wax, however currently there are a variety of materials that are used. The model is then covered with a ceramic slurry which hardens to create a mold. The original model is then dissolved (for example, wax is melted and drained), and molten metal is inserted in its place. Once cooled and the mold removed (divested), you are left with the finished piece.

In practice, modern Investment Casting is a more sophisticated process that involves many more steps than described above (see list below). Sometimes it requires multiple model components, various modeling materials, etc., and like die casting, when done well, the resulting surface quality is excellent.

 

AFTER CLAY DEEPING

Tolerance table – Based on ISO 8062 international standard

Water glassSilicon glueZircon flowerBasic dimension-mm
0.360.180.131-10
0.380.20.1410-16
0.420.220.1516-25
0.460.240.1725-40
0.50.260.1840-63
0.560.280.263-100
0.620.30.22100-160
0.70.340.24160-250
0.780.4250-400
0.3400-630
1630-1000


This table is only one factor used by the designer in specifying the recommended process. Other factors to consider include alloy type, geometry, and desired cost per unit.

CF-8M INVESTMENT

SUPER DUPLEX INVESTMENT

Typical steps in Investment Casting:
  •  Create an aluminum mold (negative pattern)
  • Wax injection (positive pattern)
  • Assembly of the pattern tree (potentially consisting of multiple patterns)
  • Covering with refractory clay, 3-8 layers deep
  • Furnace dewaxing
  • Pouring of molten metal
  • Separation from mold
  • Cutting & fettling
  • Heat treatment
  • Machining
  • Plating and other finishing process.

Advantages:

  • Suitable for complex shapes
  • Tight tolerances
  • Excellent surface quality
  • Little or no finishing processes may be required.

US  Castings offers three (3) types of Investment Casting processes:

  • Water glass (silicate)
  • Silicone glue
  • Zircon flour

All commercially available alloys can be used.

Process selection is determined by end product desired qualities and necessary mold characteristics relative to chosen alloy (for example Zircon is less apt to react with metal). Sometimes these processes are combined.

US Castings selects the optimal approach based on:

  • Required alloy
  • Part size
  • Dimensional tolerance

SUPER DUPLEX INVESTMENT

CF-8M INVESTMENT

US Castings’ engineering department is available to consult on geometric complexity, surface finish, cost and other factors. US Castings’ expertise in Value-Engineering will help to achieve the desired result at the lowest possible unit or overall cost.

ASK ABOUT OUR ZERO RISK POLICY

OR CALL US NOW 347-707-1222

Instagram  instagramUS Castings

instagram
instagram
instagram
instagram

Combining innovation, value and 25 years of experience.