Chapter 9 Fracture Testing. Impact Testing. Impact Testing. Charpy Impact Testing. (a) Charpy impact testing machine. (b) Charpy impact test specimen. (c) Izod impact test specimen. Energy Absorbed vs. Temperature. Energy absorbed versus temperature for a steel in annealed
Charpy Impact Testing
(a) Charpy impact
testing machine. (b) Charpy impact
test specimen. (c) Izod impact test
Energy absorbed versus
temperature for a steel in annealed
and in quenched and tempered
states. (Adapted with permission
from J. C. Miguez Suarez and K. K.
Chawla, Metalurgia-ABM, 34 (1978)
Effect of temperature
on the morphology of fracture
surface of Charpy steel specimen.
Test temperatures Ta < Tb < Tc <
Td. (a) Fully brittle fracture. (b, c)
Mixed-mode fractures. (d) Fully
ductile (fibrous) fracture.
Results of Charpy tests
for AISI 1018 steel (cold drawn).
Charpy V-notch curve
for a pressure-vessel steel. Note
that the NDT temperature
determined by the drop-weight
test corresponds to the high-tough
region of the Charpy curve.
Pneumatic pressurization; material:
21/4 Cr-1 Mo steel, yield stress
590 MPa. (After W. J. Langford,
Can. Met. Quart., 19 (1980) 13.)
(a) Typical oscilloscope
record of an instrumented Charpy
impact test. (b) Schematic
representation of (a).
Typical ASTM standard
plane-strain fracture toughness
test specimens. (a) Compact
tension. (b) Bending. (c)
Photograph of specimens of
various sizes. Charpy and tensile
specimens are also shown, for
comparison purposes. (Courtesy
of MPA, Stuttgart.)
Schematic of typical
load–displacement curves in a KIc
Plastic zone at the x1
crack tip in a plate of finite
measuring displacement in a
Variation in Kc with
flaw size, specimen thickness, and
mechanism of deformation.
determining JIc. (a) Load identical
specimens to different
displacements. (b) Measure the
average crack extension by heat
tinting. (c) Calculate J for each
specimen. (d) Plot J versus a to
Normal stresses along
a section of beam for linearly
Application of loads
and bending moment diagrams for
(a) three-point bending and (b)
four-point bending tests.
Shematic drawing of
the miniaturized disk-bend test.
(Adapted from H. Li, F. C. Chen,
and A. J. Ardell, Met. Trans A, 22
methods for brittle materials. (a)
Double-cantilever beam (DCB). (b)
Double torsion. (c) Notch flexure.
Chevron notch test.
(a) Schematic of the test
arrangement and the details of the
notch plane. (b) The chevron tip
length, a0, can be measured from
optical micrographs of broken
specimens. (c) Chevron short-rod
Fractures produced by
hardness indentations in (a) AsS3
glass (courtesy of B. R. Lawn and
B. J. Hockey) and (b) Al203.
representation of indentation
generating a plastic deformation
region and a semicircular crack.
conventional and indentation
fracture toughness determinations
for glasses and ceramics. (From G.
R. Anstis, P. Chankitul, B. R. Lawn,
and D. B. Marshall, J. Am. Cer. Soc.,
64 (1981) 533.)
Indentation tests for
the determination of toughness of
bond between substrate and thin
film; (a) method used for ductile
coating on brittle substrate (typical
of electronic components); (b)
method used for brittle coatings
on ductile substrate; (c) calculated
normalized energy release rate as
a function of normalized crack
diameter. (Adapted from J. J.
Vlassak, M. D. Drory, and W. D.
Nix, J. Mater. Res., 12 (1997) 100.)