scholarly journals International seminar on high temperature fracture mechanisms and mechanics

1987 ◽  
Vol 28 (1) ◽  
pp. 113
Keyword(s):  
High Temperature ◽  
International Seminar ◽  
Fracture Mechanisms ◽  
Temperature Fracture

Microstructure and Tensile Properties of 1-D Forged (TiB+TiC)/Ti Composite

2013 ◽  
Vol 747-748 ◽  
pp. 926-931 ◽  
Author(s):  
Chang Jiang Zhang ◽  
Fan Tao Kong ◽  
Shu Long Xiao ◽  
Li Juan Xu ◽  
Yuong Chen ◽  
...  
Keyword(s):  
High Temperature ◽  
Aspect Ratio ◽  
Grain Boundaries ◽  
Tensile Properties ◽  
Room Temperature ◽  
Fracture Mechanisms ◽  
Cast Composite ◽  
Temperature Fracture ◽  
Cast Microstructure

In this work, 2.5vol. % (TiB+TiC)/Ti composite was prepared by in situ casting route then 1-D forging. The microstructure and tensile properties were presented and discussed. The results indicate that the as cast microstructure can be significantly modified by 1-D forging. After forging, TiB and TiC segregated at the prior β grain boundaries within the as-cast composite tend to fracture and align perpendicular to forging direction. Reduction in aspect ratio of reinforcements and α lath is also observed. 1-D forging can enhance the strength and elongation of as cast composite significantly. However, the increment in strength is quite limited as strain temperature increases to 700 °C. Additionally, room temperature and high temperature fracture mechanisms are also discussed.

scholarly journals High temperature fracture mechanisms on non-oriented electrical steels

2007 ◽  
Vol 43 (4) ◽  
Author(s):  
E. O. García-Sánchez ◽  
E. A. Treviño-Luna ◽  
A. Salinas-Rodríguez ◽  
L. A. Leduc-Lezama
Keyword(s):  
High Temperature ◽  
Fracture Mechanisms ◽  
Electrical Steels ◽  
Temperature Fracture

Tensile Behaviour of Al-Si Alloy and Al-Si/Graphite Composites at Elevated Temperatures

2012 ◽  
Vol 710 ◽  
pp. 457-462 ◽  
Author(s):  
G. Rajaram ◽  
S. Kumaran ◽  
T Srinivas Rao
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Matrix Alloy ◽  
Tensile Behaviour ◽  
Fracture Mechanisms ◽  
Strain Hardening Exponent ◽  
Transition Elements ◽  
Softening Effect ◽  
Graphite Composite

The high temperature tensile behaviour of Al-Si alloy and two of its composite systems with graphite as major reinforcement were investigated. The composites were developed by the stir casting method, wherein a mixture of graphite (3 wt %) and Cu / Ni (2 wt% each) were added into the molten Al-Si alloy to fabricate two systems such as Al-Si-Cu/graphite composite and Al-Si-Ni/graphite composite. The properties of composites were better than that of the matrix alloy. Tensile behaviour of alloy and composites were studied at different temperatures from room temperature to 300°C. It is found that the tensile strength of the alloy and composites were decreasing with increase in temperature. The transition elements (Cu / Ni) have played the key role in improving the ultimate tensile and yield strength of the composites over the alloy. The flow stress of the composite is more than that of the alloy. The strain hardening exponent value continuously drops with the increase of tensile temperature due to the thermal softening effect. The % elongation of the alloy is more than that of the composites. Fracture surfaces of the samples are analyzed by scanning electron microscope to understand the fracture mechanisms. Fractography reveals that the fracture behaviour of the alloy changes from cleavage mode at room temperature to complete ductile mode at high temperature.

Analyses of Eutectoid Phase Transformations in Nb–SilicideIn SituComposites

2004 ◽  
Vol 10 (4) ◽  
pp. 470-480 ◽  
Author(s):  
B.P. Bewlay ◽  
S.D. Sitzman ◽  
L.N. Brewer ◽  
M.R. Jackson
Keyword(s):  
Crystal Structure ◽  
Phase Transformation ◽  
High Temperature ◽  
Room Temperature ◽  
Bulk Composition ◽  
High Strength ◽  
Eutectoid Decomposition ◽  
Quaternary Alloys ◽  
Temperature Fracture

Nb–silicide in situ composites have great potential for high-temperature turbine applications. Nb–silicide composites consist of a ductile Nb-based solid solution together with high-strength silicides, such as Nb5Si3and Nb3Si. With the appropriate addition of alloying elements, such as Ti, Hf, Cr, and Al, it is possible to achieve a promising balance of room-temperature fracture toughness, high-temperature creep performance, and oxidation resistance. In Nb–silicide composites generated from metal-rich binary Nb-Si alloys, Nb3Si is unstable and experiences eutectoid decomposition to Nb and Nb5Si3. At high Ti concentrations, Nb3Si is stabilized to room temperature, and the eutectoid decomposition is suppressed. However, the effect of both Ti and Hf additions in quaternary alloys has not been investigated previously. The present article describes the discovery of a low-temperature eutectoid phase transformation during which (Nb)3Si decomposes into (Nb) and (Nb)5Si3, where the (Nb)5Si3possesses the hP16 crystal structure, as opposed to the tI32 crystal structure observed in binary Nb5Si3. The Ti and Hf concentrations were adjusted over the ranges of 21 to 33 (at.%) and 7.5 to 33 (at.%) to understand the effect of bulk composition on the phases present and the eutectoid phase transformation.

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