Metal casting

Expendable mold casting methods

• Expendable mold casting includes sand, plastic, shell, plaster, and investment (lost-wax technique) moldings.
• These methods use temporary, non-reusable molds.
• Widely used for casting complex shapes in industries such as automotive, aerospace, and medical devices.
• Offers cost-effective production of small to medium-sized batches.

Non-expendable mold casting methods

• Non-expendable mold casting does not require reforming the mold after each production cycle.
• Includes permanent, die, centrifugal, and continuous casting methods.
• Improves repeatability and delivers near net shape results.

Specific casting methods

• Sand casting is one of the most popular and simplest types of casting.
• Loam molding is used for producing large symmetrical objects like cannon and church bells.
• Plaster mold casting uses plaster of paris as a mold material.
• Shell molding provides a finer surface finish compared to sand casting.
• Investment casting, also known as lost-wax casting, is suitable for producing net shape components with high accuracy and repeatability.

Casting theory

• Casting is a solidification process that controls most properties of the casting.
• Casting defects, such as gas porosity and solidification shrinkage, occur during solidification.
• Cooling curves are important for controlling the quality of a casting.
• Chvorinov's rule calculates the local solidification time of a casting.
• The gating system conveys the liquid material to the mold and controls various factors.
• Shrinkage occurs during solidification and can be controlled through directional solidification, risers, and chills.

Macrostructure and casting process simulation

• The grain macrostructure in ingots and most castings have three distinct regions: the chill zone, columnar zone, and equiaxed zone.
• Casting process simulation uses numerical methods to calculate cast component quality, including mold filling, solidification, and cooling.
• Simulation accurately describes a cast component's quality before production starts, reducing the need for pre-production sampling.

Metal casting Data Sources