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ASTM E604 is the standard test method for Dynamic Tear testing of metallic materials
as defined by ASTM International. The Dynamic Tear test is used on specimens ranging
in thickness from 3/16in. to 5/8in. (5mm to 16mm). The pressed-knife
procedure commonly used to sharpen the notch tip effectively limits this
testing method to materials with a hardness of less than 36 on the Rockwell
C scale.
This test
involves a single-edge notched beam that is impact loaded in three-point
bending; The specimens are then fractured with a drop-weight machine, and
the total energy loss during separation is measured by finely calibrated
instrumentation and recorded based on time vs. load data.
The resulting dynamic tear energy value is significant
in that the specimen's resistance to rapid progressive fracturing can be
determined. This can be invaluable in determining suitability of a material
or fabricating process for a particular application.
It is also quite important in
research and development to gage the impact of metallurgical
factors, such as: composition, processing, or heat treatment, and of
fabricating factors such as: forming and welding processes on the dynamic
tear fracture resistance of new or existing materials. |
