Stainless Steel Investment Casting
The Investment casting (by “Lost-wax”) process techniques was derived from the ancient casting method used among Egyptians over about 5,000 years ago for producing Jewelleries, Artistic items and images of deities with extremely minute details.
Now, this ancient technique has become most preferring method to produce dimensionally accurate high-precision casting components in various industries around the globe using with high temperature resistant ceramic moulding materials & binders. This casting method has a lot of advantages in comparison with other variety of casting processes. When the other processes fail to succeed, the castings of engineering parts and other various mechanical parts having small sizes to big different shapes can be manufactured quickly in large quantities through investment casting by “Lost-wax” process.
The “Lost-wax” casting process starts from injecting molten wax into a designed Mould to form Wax Pattern of the desired component. These wax pattern’s are assembled to a wax mould which is called ‘tree’.
There after this tree is coated with ceramic based slurry with number of coats and dried in controlled atmosphere. After the ceramic based slurry coats are dried, then the wax is removed from the mould which is known as a De-waxing process. Hence this process is called as a “Lost-wax process”. The internal cavity after de-waxing is called “Shell or Ceramic Mould”. The molten metal is then poured into the “Shell or Ceramic Mould” which are heated along with the metal and allowed to cool. Finally, the external mould is broken and the castings are retained.
The ability to cast thin wall parts with close tolerance and stability is an advantage of investment casting. The final products will have smooth surface finishing. Machining can be eliminated or reduced along with best finish in ‘As cast’ condition.
Advantages of Investment Castings :
Liberty of Design :
This casting method offers the greatest flexibility of construction of complex structures, artistic design and gives sophisticated appearance to the castings. This special technology also offers the freedom of design because; undercuts, thin wall-thickness / 3-dimensionally shaped areas can be produced. This versatile process allows to produce an extensive range of products for a variety of industries.
Freedom In Selection of Vast Variety of Materials :
It allows freedom in selection of suitable alloys. All ferrous based steel and stainless steel materials as per Global Standards can be produced.
Dimensional Control :
This process allows to achieve the precise dimensional control which may lead to eliminate machining of the component by getting the desired dimensional accuracy in ‘As cast’ condition along with saving of machining cost and time also.
High Quality Surface Finish :
The process allows to achieve high quality surface finish.
Fabricated Parts :
Many fabricated parts can be converted into castings by simple designing and developing the same into single piece component. This will lead to cost-saving as well as time eliminating welding, assembling and machining of the product. Also, the products can be manufactured in larger quantity which will not be possible by fabrication process.
Re-Production Of Fine Details :
This casting method gives the freedom for perfect re-production of fine details viz. slots, holes and case lettering etc.