Last bit of casting info

slides 123 - 146

General Casting Defects

1. Misrun: solidified before filling whole cavity

2. Shrinkage Cavity: depression in surface cause by solidification shrinkage

Foundry Inspection Methods

Visual inspection, dimensional measurements, and metallurgical or chemical

Castability

ease with which a cast part can be produced

based on…

1. Part Design

2. Casting Metal

3. Proper selection of casting process

Casting metals

Processes done after casting has solidified

1. Trimming: remove sprues, runners, risers, parting lines, etc.

2. Remove Core: manually, mechanically, or chemically

3. Surface Cleaning: remove sand from surface by tumbling, air blasting or wire brushing

4. Inspection: detect quality defects

5. Repair: if required and/or possible

6. Heat Treatment: enhance processes or subsequent machining

Classification of Casting Quality Defects

1. General Defects: common to all casting processes

2. Defects related to sand casting process

Sand Casting Defects

1. Infiltration: when fluidity of liquid metal is high it may infiltrate the sand mold or core

2. Mold Shift: step in the casting at the parting line caused by displacement of cope and drag