On the relation between fracture surface characteristics and material properties

Author(s):  
C.L. Briant

Grain boundary segregation is the process by which solute elements in a material diffuse to the grain boundaries, become trapped there, and increase their local concentration at the boundary over that in the bulk. As a result of this process this local concentration of the segregant at the grain boundary can be many orders of magnitude greater than the bulk concentration of the segregant. The importance of this problem lies in the fact that grain boundary segregation can affect many material properties such as fracture, corrosion, and grain growth.One of the best ways to study grain boundary segregation is with Auger electron spectroscopy. This spectroscopy is an extremely surface sensitive technique. When it is used to study grain boundary segregation the sample must first be fractured intergranularly in the high vacuum spectrometer. This fracture surface is then the one that is analyzed. The development of scanning Auger spectrometers have allowed researchers to first image the fracture surface that is created and then to perform analyses on individual grain boundaries.


2015 ◽  
pp. 439-485

This chapter describes the causes of cracking, embrittlement, and low toughness in carbon and low-alloy steels and their differentiating fracture surface characteristics. It discusses the interrelated effects of composition, processing, and microstructure and contributing factors such as hot shortness associated with copper and overheating and burning as occur during forging. It addresses various types of embrittlement, including quench embrittlement, tempered-martensite embrittlement, liquid-metal-induced embrittlement, and hydrogen embrittlement, and concludes with a discussion on high-temperature hydrogen attack and its effect on strength and ductility.


2009 ◽  
Vol 416 ◽  
pp. 593-597
Author(s):  
Jian Yun Shen ◽  
Xi Peng Xu

Brittle materials are popularly used as engineering materials for excellent properties. But the properties of brittle materials are different and special, and cause to different surface formation mechanism during the grinding process. In the study, surface roughnesses after grinding with different mesh size diamond wheels were measured. Combined with scanned surface topographies, the relation between the surface roughness and the properties of these brittle materials was discussed. It could be found that the material properties led to the different surface characteristics of brittle materials.


2011 ◽  
Vol 264-265 ◽  
pp. 355-360 ◽  
Author(s):  
Saeid Norouzi ◽  
Hassan Farhangi

In the present study, the effect of cooling condition on hot tearing tendency and hot tearing fracture surface morphology were investigated. Results show that, the hot tear fracture surface characteristics are nearly similar under different cooling conditions. The hot tear surface exhibits two main features; the brittle region and the ductile region. The results also indicate that cooling condition has multifaceted effects on hot tearing phenomenon. Increasing cooling rate increases the thermal gradient, which raises the hot tearing tendency; concomitantly it decreases the grain size and dendrite arm spacing which increases the strength of the material. The occurrence of hot tearing phenomenon under different cooling conditions is discussed and evaluated based on the competition between these opposing factors during the solidification process.


2014 ◽  
Vol 59 ◽  
pp. 62-71 ◽  
Author(s):  
Mingliang Li ◽  
Wim van Keulen ◽  
Martin van de Ven ◽  
André Molenaar ◽  
Guoqi Tang

1986 ◽  
Vol 72 ◽  
Author(s):  
Darrel Frear ◽  
Dennis Grivas ◽  
Lenora Quan ◽  
J. W. Morris

AbstractThe microstructure and mechanical properties of Pb-Sn solder joining Cu plates were studied. Yticrostructural observations were made on both the bulk Pb-Sn solder and on the interface between the solder and Cu plates. Pb-Sn solder has a two-phase microstructure in which the Pb-rich phase is the weaker. β-Sn precipitates in the Pb-rich phase were characterized in TEM. Intermetallic phases (Cu6 Sn5 and Cu3Sn) that form during the reaction of molten Pb-Sn solder with Cu were investigated. Solder joints were tested to fracture in both shear and tensile configurations. The mechanical properties and fracture surface characteristics are reported.


2020 ◽  
Vol 20 (7) ◽  
pp. 4235-4238
Author(s):  
Ju-Hwan Choi ◽  
Henzeh Leeghim ◽  
Ju-Hun Ahn ◽  
Dae-San Choi ◽  
Chang-Yull Lee

In this paper, surface characteristics of 3D printed structures fractured at low temperature environments are analyzed. The samples are fabricated by using ABS (acrylonitrile butadiene styrene copolymer) material, and the structures are constructed by the well-known honeycomb models using a FDM-Type 3D printer. To analyze the fracture surface of the samples constructed uniquely by using the 3D printer, the bending loads are applied to the samples at 30, −10 and −50 °C, respectively. The characteristics of the fracture surfaces of the 3D samples are also observed by the FE-SEM (field emission scanning electron microscope) equipment. From this experiment, it is evaluated that the fractured surface of the 3D sample is very rough at 30 °C, while it is smooth at a relatively low temperature. Also, several unique features of the fracture surface of a 3D printed sample structured by honeycomb models are also examined.


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