ASM Metals HandBook Volume 12 - Fractography
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ASM Metals HandBook Volume 12 - Fractography


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Results of an Experimental Inquiry into the Tensile Strength and Other Properties of Various 
Kinds of Wrought Iron and Steel, 1862 
19. E.F. Dürre, Über die Constitution des Roheisens und der Werth seiner Physikalischen Eigenschaften, 1868; 
preliminary version in Berg- und Hüttenmannischen Zeitung (1865 and 1868) and in Zeitschrift für das 
Berg-Hütten- und Salienen-wesen, Vol 16, 1868, p 70-131, 271-301 
20. D.K. Tschernoff, Kriticheskii Obzor Statiei gg. Lavrova y Kalakutzkago o Stali v Stalnikh Orudiakh' i 
Sobstvennie ego Izsledovanie po Etomuje Predmetu (Critical Review of Articles by Messrs. Lavrov and 
Kalakutzkii on Steel and Steel Ordnance, with Original Investigations on the Same Subject), in Zapiski 
Russkago Tekhnicheskago Obshestva, 1868, p 399-440; see English translation by W. Anderson of 
Tschernoff's original contribution (p 423-440 only), On the Manufacture of Steel and the Mode of Working 
It, Proc. Instn. Mech. Engrs., 1880, p 286-307; see also French translation, Rev. Univ. Mines, Vol 7, 1880, p 
129 
21. D.K. Tschernoff, Izsledovanie, Otnosiashchiasia po Struktury Litikh Stalnykh Bolvanok (Investigations on 
the Structure of Cast Steel Ingots), in Zapiski Imperatorskago Russkago Teckhnicheskago Obshestva, 1879, 
p 1-24; see English translation by W. Anderson, Proc. Instn. Mech. Engrs., 1880 p 152-183 
22. J. Percy, Metallurgy, Vol 1 to 4, John Murray, 1861-1880 
23. A. Martens, Über die Mikroskopische Untersuchung des Eisens, Z. Deut. Ing., Vol 22, 1878, p 11-18 
24. A. Martens, Zur Mikrostruktur des Spiegeleisens, Z. Deut. Ing., Vol 22, 1878, p 205-274, 481-488 
25. A. Martens, Ueber das Kleingefüge des Schmiedbaren Eisens, Stahl Eisen, Vol 7, 1887, p 235-242 
26. J.A. Brinell, Über die Texturveränderungen des Stahls bei Erhitzung und bei Abkühlung, Stahl Eisen, Vol 
11, 1885, p 611-620 
27. H.M. Howe, The Metallography of Steel and Cast Iron, McGraw-Hill, 1916, p 527, and Table 29 on p 534-
535. (Translation and condensation, with slight amendments, of original diagram from ref 19, p 611) 
28. B. Kirsh, Beiträge zum Studium des Fliessens, Mitt Hlg, 1887, p 67; 1888, p 37; 1889. p 9; see also G.C. 
Hennings, Adolf Marten, Handbook of Testing of Materials, Part I, John Wiley & Sons, 1899, p 103, 105 
History of Fractography 
Development of Microfractography 
Most of the microscopical studies of metals in the early 1900s were limited to examinations of polished specimens. In the 
1930s, a number of investigators recognized that the properties of steels could be correlated with the macroscopic 
coarseness or fineness of the fracture surface. For example, Arpi developed a set of standard fracture tests (the 
Jernkontoret fracture tests) that was believed to cover the entire grain size range (Ref 29, 30). Similarly, Shepherd 
developed a set of standards for evaluating grain size in hardened tool and die steels (Ref 31, 32, 33). His method remains 
in limited use. 
However, it was not until the work of Zapffe and his co-workers (Ref 1, 3, 34 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 
46, 47, 48, 49, 50) in the decade 1940 to 1950 that significant, detailed studies of the microscopic elements of fractures 
were brought to the attention of the scientific community. Zapffe's work on application of the light microscope to 
fractography was regarded by many as definite (Ref 51). 
Although bothered by the relatively small depth of focus of the light microscope, Zapffe and his co-workers were able to 
orient the facets of a fracture relative to the axis of the microscope so that examinations could be made at relatively high 
magnifications. (Zapffe routinely took fractographs with magnifications as high as 1500 to 2000×.) Most of Zapffe's work 
was done on brittle fractures in ingot iron and steels (notably welded ship plate, Ref 48), bismuth (Ref 35), zinc (Ref 37), 
antimony (Ref 42), molybdenum (Ref 44), and tungsten (Ref 45), from which he described in considerable detail the 
appearance and crystallography of cleavage facets. Figures 5(a) and 5(b) are examples of Zapffe's early work. 
 
Fig. 5 Cleavage fractures in room-temperature impact specimens examined by C.A. Zapffe. (a) Cast 
polycrystalline antimony (99.83Sb-0.04S-0.035As-0.035Pb-0.015Fe-0.01Cu) (b) Vacuum-arc-cast high oxygen 
molybdenum 
In the case of cleavage, Zapffe made a detailed study of the relationship among crystallographic orientation, structure, and 
the characteristics of the fracture surface, particularly in iron-silicon (Ref 43) and iron-chromium alloys (Ref 38, 43, and 
49). Zapffe and Clogg also described the modifications to the appearance of the fracture surface when a second phase is 
present (Ref 1). In the case of tungsten, Zapffe and Landgraf observed, depending on the composition, pure cleavage 
fracture or a mixed fracture mode consisting of cleavage and intergranular fracture (Ref 45). They succeeded in 
photographing the intergranular zones at high magnification, the features of which are analogous to those observed in 
electron fractography (Ref 51). 
Metallic cleavage has subsequently been the subject of a large number of optical fractography studies. Two papers were 
of particular importance. One was by Tipper and Sullivan (Ref 52) on the relationship between cleavage and mechanical 
twinning in iron-silicon alloys. The other was by Klier (Ref 53), who in 1951 used x-ray diffraction in addition to the light 
microscope in his work on cleavage in ferrite. In a written discussion following Klier's paper, Zapffe wrote, "Dr. Klier's 
photographs are splendid from both a photographic and a technical standpoint. He has in addition brought the important 
tool of X-ray diffraction to bear upon the problem, also the electron microscope." 
According to Henry and Plateau (Ref 51), Zapffe and his colleagues were also the first to observe striations on fatigue 
fracture surfaces (Ref 50). In describing the striations, observed in an aluminum alloy 75S-T6 (equivalent to present-day 
7075). Zapffe wrote, "This fine lamellar structure seems clearly to be a fatigue phenomenon, suggesting a stage of minute 
structural ordering advanced beyond the grosser platy structure, and apparently favored by an increasing number of stress 
cycles. The lamellae are approximately parallel to the platy markings; and both sets of markings lie approximately in the 
bending plane perpendicular to the stress motion, as one would expect for a structural rearrangement due to this type of 
flexion." Figure 6 shows one of the fractographs included in Zapffe and Worden's 1951 paper "Fractographic 
Registrations of Fatigue" (Ref 50). 
 
Fig. 6 Fatigue striations observed by Zapffe (Ref 50) in an aluminum alloy specimen tested in completely 
reversed bending, at a maximum stress of 172 MPa (25 ksi) at room temperature, to failure at 336× 103 cycles 
Although the above-mentioned studies with the light microscope were of tremendous value, it must be pointed out that 
they were mainly limited to cases in which the fractures consisted of relatively large flat facets, ideal subjects for optical 
fractography. Consequently, detailed studies of ductile fracture morphologies were not made possible until the advent of 
electron fractography. For additional information on the applications and limitations of the light microscope for fracture 
studies, see the article "Visual Examination and Light Microscopy" in this Volume. 
 
References cited in this section 
1. C.A. Zapffe and M. Clogg, Jr., Fractography--A New Tool for Metallurgical Research, Preprint 36, 
American Society for Metals, 1944; later published in Trans. ASM, Vol 34, 1945, p 71-107 
3. C.A. Zapffe and C.O. Worden, Temperature and Stress Rate Affect Fractology of Ferrite Stainless, Iron 
Age, Vol 167 (No. 26), 1951, p 65-69 
29. R. Arpi, Report on Investigations Concerning the Fracture Test and the Swedish Standard Scale, 
Jernkontorets