The investment casting (or lost wax) process begins with creating a wax pattern of the desired part or product, coating it with a ceramic shell, and then melting the wax out to create a mold cavity. Hot liquid metal is then poured into that mold cavity to create the final metal product. Investment casting is ideal for intricate and tighter tolerance parts. Small to medium-sized parts are a good fit for investment casting.
Investment Casting Advantages
The first advantage of investment casting is to produce parts with fine detail (i.e. part with internal cavities and have complex shapes), excellent surface finish, and tight tolerance. Second is the ability to cast thinner parts. The benefit of thin-walled parts is a lighter-weight(lower cost) part. Third advantage of investment casting is the ability to work with ferrous metals, especially stainless steel and heat-resistant alloys. Investment casting is ideal for low to medium volume projects.
Investment Casting Disadvantages
Investment casting has limitations, like other casting processes. It is typically more expensive than other casting methods, and it is not well-suited for producing extremely large parts. Additionally, investment casting molds can be complex and time-consuming to manufacture. The cycle time for investment casting is longer than other casting methods, which raises the cost. Making one investment casting need relatively longer time. The primary reason is that the mold for each investment casting needs to be remade each time.
Sand Casting
The sand-casting method forms a mold by packing sand around a pattern of the desired part or product. The pattern is then removed, and molten metal is poured into the cavity to create the final part. Sand casting is a highly versatile casting method that has flexibility when it comes to sizes, shapes, and materials required.
Sand Casting Advantages
The sand-casting method is excellent for larger parts as there is more flexibility and lower cost to produce the molds. Lower production runs are a great fit for sand castings. Sand casting is ideal for parts that do not require tight dimensional tolerances or high degrees of machining.
Sand Casting Disadvantages
As mentioned above, sand casting is typically not well-suited for producing parts with high dimensional accuracy and consistency. The rough finishes can require additional machining, but many sand casted parts do not require smooth finishes.
Conclusion:
Investment casting, and sand casting are casting methods that have unique advantages and disadvantages. Investment casting allow for tight dimensional tolerances and are great for small, intricate parts. Sand casting is better suited for larger parts that do not require complex machining. Scale of production and costs come into play quickly for the two methods. Selecting the correct casting method can be a complex decision at times, but Qianhao experts are here to support customers with investment casting, sand-casting, and lost foam casting solutions.