Factors Affecting Tensile Properties of Castings 2004-01-1021
The basic data on the mechanical properties of a casting are frequently obtained from a tensile test, in which a suitable specimen machined from the casting is subjected to increasing axial load until it fractures. The engineering tension test is widely used by casting manufacturers as an acceptance test for customer specifications. However, tensile bars machined from castings often provide undesirable information, thereby leading one to question the part integrity.
This paper, therefore, discusses the various factors that affect tensile properties obtained from specimens machined from actual castings. These factors include:
Type of casting process
Wall thickness of castings
Size and distribution of inclusions in a tensile bar
Type and distribution of porosity in a tensile bar
Size and shape of tensile bar
Location of tensile bar in a casting
Results from this investigation indicate that achieving undesirable tensile properties do not necessarily indicate that a part would not perform its intended function satisfactorily.