Chapter 5 Overview Casting die is the other major component Casting die has four functions: Hold molten metal in shape of desired casting Provide means for molten metal to get into the space where it is held in desired shape Remove heat from molten metal to solidify it Provide for removal of the solidified metal

Chapter 5 Objectives Identify the four types of casting dies Identify the three major casting die modules Identify the purpose of each major die component Review course objectives. Tell participants that all testing will be based on the course and chapter level objectives.

New Terms Cavity Gate OEM Overflows/lifters The void or empty space in the die that fills with metal to make the casting Gate The smallest restriction in the alloy flow path, located at the edge of the casting OEM Acronym for Original Equipment Manufacturer Overflows/lifters Small pockets of alloy located around the edge of the casting Discuss sand, investment, and lost foam casting. Use gravity to fill the mold. The mold is destroyed to remove the casting. Mold making is as important part as is making the casting. Metal flow is slow. Walls are much thicker than in die casting. Cycle time longer because of inability of mold material to remove heat. Discuss permanent mold casting. A cousin to die casting. The mold is reused, not destroyed. The process uses gravity to fill the casting. Mold is steel with comparatively good thermal conductivity, hence the release agents used in this process are also insulators. This keeps the casting from freezing periodically and prevents filling. Machines for this process are smaller than machines used to die cast for similar sized castings. Discuss centrifugal casting. Frequently made by jewelers. The choice for low volume castings with a small amount of pressure. The molds are placed around the circumference of a centrifuge. As the centrifuge spins, metal is poured in at the center and centrifugal force distributes the metal to the molds.

New Terms cont. Runner Shot Vent Vacuum vent Die cast alloy distribution system within the casting die Shot All the injected material Vacuum vent Helps get the air out of the die cavity. Vent Path from the die cavity to outside the die Discuss sand, investment, and lost foam casting. Use gravity to fill the mold. The mold is destroyed to remove the casting. Mold making is as important part as is making the casting. Metal flow is slow. Walls are much thicker than in die casting. Cycle time longer because of inability of mold material to remove heat. Discuss permanent mold casting. A cousin to die casting. The mold is reused, not destroyed. The process uses gravity to fill the casting. Mold is steel with comparatively good thermal conductivity, hence the release agents used in this process are also insulators. This keeps the casting from freezing periodically and prevents filling. Machines for this process are smaller than machines used to die cast for similar sized castings. Discuss centrifugal casting. Frequently made by jewelers. The choice for low volume castings with a small amount of pressure. The molds are placed around the circumference of a centrifuge. As the centrifuge spins, metal is poured in at the center and centrifugal force distributes the metal to the molds.

Die Ownership The OEM owns the tooling required to make the die casting If GM opted to purchase casting from a custom producer, the custom producer would buy casting die from a toolmaker and then sell the die to GM If GM opted to manufacturer the casting in its own plant, GM would buy the die from a toolmaker directly

Types of Dies Single cavity die Multiple cavity die Family die Produces one casting at a time Multiple cavity die Produces more than one casting at a time Family die Produces a number of different parts Unit die OEM owns the unit die and the custom die caster owns the mold base or unit die holder

Unit Die System Advantages Disadvantages Lower tooling costs Shorter lead times Potentially lower piece part costs Disadvantages Reduced flexibility in part design Limited size Possible problem moving tooling from one vendor to another without additional tooling costs

Mold base Steel envelope that is designed to hold all the other die components together Usually made from a pre-hardened steel such as a P-20 or AISI 4140

Stationary half mold base Acts as container for stationary die cavities Provides means for attaching stationary die half to machine Couples injection system to the die Provides a means for aligning to two die halves Has several components

Stationary Half Mold Base Components Clamp slots Guide pins Pryslots Mounting/clamp plate

Moving half mold base Acts as container for the die cavities Couples ejection system to the cavities Provides means for aligning the two die halves Components include: Guide bushings

Ejector box Provides a means for mounting moving half mold base to moving machine platen Supports moving half mold base against machine closing force and force of injection Couples machine ejector system to die ejector system Has several components

Ejector Box Components Parallels/rails Clamp plate Support pillars

Ejector system Inside the ejector box Provides one of four critical die functions, to ‘provide for removal of the solidified metal’ Has several components

Ejector System Components Ejector pins Return pins Ejector plate Ejector return plate Guided ejection

Die Cavity Cavity blocks Core pins Slides Carrier Wedgelock Cam pin Cooling lines Heaters Casting Core pin

Die Cavity cont. Several cavity features share same terminology as the die cast shot Sprue Runner Gate Overflows Vents

Miscellaneous Components Biscuit block Sprue bushing Sprue post Stop buttons Quick eject cam and pins

Summary Casting die is the other major component Has four functions Castings can be manufactured by the OEM or purchased from a custom producer 4 casting die forms: single cavity, multiple cavity, family and unit A typical die contains 3 modules: stationary mold base, moving mold base and ejector box

Summary cont. Unit dies are not complete dies; have certain advantages and disadvantages for the OEM There are many components to casting dies Mold base Stationary half mold base Moving half mold base Ejector box Ejector system Die cavities