Sand Casting

Process Definition & Working Principle

Sand casting is a foundational gravity-driven metal casting process where a molten metal charge is poured into a cavity formed within a compacted aggregate mixture. Upon solidification, the aggregate mold is mechanically destroyed: a process designated as shake-out: to recover the finished part. The process is highly versatile, permitting the casting of virtually all metal alloys in mass ranges from several grams to hundreds of tons.

Physicochemical Composition of Molds and Binders

A sand mold operates as a transient thermodynamic reactor consisting of:

Kinematics, Axes, & Machine Configuration

Sand casting operations rely on an integrated train of mechanical systems to ensure precise tooling fabrication, high-speed mold compaction, and synchronized metal pouring.

CNC Machining of Pattern Equipment

3-axis and 5-axis portal CNC routers are utilized for high-speed machining of pattern assemblies.

Tooling & Cutting Geometry

The construction of a sand mold entails multiple structural features designed to regulate the velocity of the liquid charge, trap inclusions, and feed volumetric contraction.

Anatomy of a Sand Mold Assembly

• Cope: The upper half of the molding box (flask).
• Drag: The lower half of the molding box.
• Cheek: An intermediate molding box section inserted between the cope and drag to accommodate complex geometries requiring multiple parting lines.

Gating System Engineering

The gating channels are dimensioned utilizing fluid dynamics to guarantee non-turbulent, laminar flow.

1. Pouring Basin: A basin at the sprue inlet designed to decelerate the poured metal and float off slag and oxides.