Strong Interface in CMCs, a Condition for Efficient Multilayered Interphases

1994 ◽  
Vol 365 ◽  
Author(s):  
Christine Droillard ◽  
Jacques Lamon ◽  
Xavier Bourrat
Keyword(s):  
Fracture Toughness ◽  
Bonding Strength ◽  
High Strength ◽  
Interfacial Behavior ◽  
Strain Behavior ◽  
High Toughness ◽  
Sic Fiber ◽  
Sliding Mechanism ◽  
Fiber Treatment ◽  
Sic Composites

ABSTRACTA fiber treatment was used to change the bonding strength of the Nicalon NLM 202 SiC fiber from weak to strong, in a series of 2D-SiC/SiC composites with multilayered interphases. The materials with the pre-treated fibers were compared to the same materials but reinforced with as received fibers. The stress-strain behavior and the fracture toughness were examined as a function of crack patterns identified by TEM. All the materials could be grouped into two distinct families: (i) materials reinforced with untreated fibers have a weak fiber bonding and are characterized by a low strength and a low toughness and (2) materials with the pre-treated fibers have a strong fiber bonding and are characterized by a high strength and a high toughness. This latter behavior is identified by TEM. It corresponds to a new interfacial behavior with a cohesive mode of interfacial cracking, involving branching and deflection by the successive interfaces. In the former family, the adhesive interfacial failure mode corresponds to the classical debond/sliding mechanism.

DILLIMAX 500

Alloy Digest ◽  
2012 ◽  
Vol 61 (3) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Physical Properties ◽  
Structural Steel ◽  
Tensile Properties ◽  
High Strength ◽  
Heat Treating ◽  
Fine Grained ◽  
High Toughness ◽  
Minimum Yield

Abstract Dillimax 500 is a high-strength quenched and tempered, fine-grained structural steel with a minimum yield strength of 500 MPa (72 ksi). Plate is delivered in three qualities: basic, high toughness, and extra tough. This datasheet provides information on composition, physical properties, and tensile properties as well as fracture toughness. It also includes information on surface qualities as well as forming, heat treating, and joining. Filing Code: SA-645. Producer or source: Dillinger Hütte GTS.

TLS S1

Alloy Digest ◽  
2007 ◽  
Vol 56 (9) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Physical Properties ◽  
Carbon Content ◽  
High Strength ◽  
Heat Treating ◽  
High Toughness

Abstract The carbon content in TLS S1, about 0.5%, produces a combination of high strength and high toughness with medium wear resistance. Chisels and rivet sets are typical applications. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on wear resistance as well as heat treating and machining. Filing Code: TS-655. Producer or source: Timken Latrobe Steel.

High Toughness Ceramic Laminates by Design of Residual Stresses

2001 ◽  
Vol 702 ◽  
Author(s):  
Nina A. Orlovskaya ◽  
Jakob Kuebler ◽  
Vladimir I. Subotin ◽  
Mykola Lugovy
Keyword(s):  
Fracture Toughness ◽  
Residual Stresses ◽  
Damage Tolerance ◽  
High Strength ◽  
Ceramic Composites ◽  
Tensile Stresses ◽  
High Toughness ◽  
Apparent Fracture Toughness ◽  
Layered Ceramics ◽  
Compressive Residual Stresses

ABSTRACTMultilayered ceramic composites are very promising materials for different engineering applications. Laminates with strong interfaces can provide high apparent fracture toughness and damage tolerance along with the high strength and reliability. The control over the mechanical behavior of laminates can be obtained through design of residual stresses in separate layers. Here we report a development of tough silicon nitride based layered ceramics with controlled compressive and tensile stresses in separate layers. We design laminates in a way to achieve high compressive residual stresses in thin (100-150 micron) Si3N4 layers and low tensile residual stresses in thick (600-700 micron) Si3N4-TiN layers. The residual stresses are controlled by the amount of TiN in layers with residual tensile stresses and the layers thickness. The fracture toughness of pure Si3N4(5wt%Y2O3+2wt%Al2O3) ceramics was measured to be of 5 MPa m1/2, while the apparent fracture toughness of Si3N4/Si3N4-TiN laminates was in the range of 7-8 MPa m1/2 depending on the composition and thickness of the layers.

Influences of Thermal Molding Process on the Flexural Properties of SiC/SiC Composites with a New Precursor Polymer

2015 ◽  
Vol 816 ◽  
pp. 33-39
Author(s):  
Zheng Luo ◽  
Xin Gui Zhou ◽  
Jin Shan Yu ◽  
Fei Wang
Keyword(s):  
Fracture Toughness ◽  
Silicon Carbide ◽  
Molding Pressure ◽  
Flexural Properties ◽  
Cross Linking ◽  
Matrix Composites ◽  
Molding Process ◽  
Sic Fiber ◽  
Precursor Polymer ◽  
Sic Composites

Silicon carbide (SiC) fiber reinforced SiC matrix composites (SiC/SiC) were fabricated by precursor impregnation and pyrolysis (PIP) process with a new precursor polymer, liquid polyvinylcarbosilane (LPVCS). The molding process was conducted during the cross-linking reactions of LPVCS for the first PIP cycle. The influences of molding pressure and molding time on the flexure properties of the SiC/SiC composites were studied. The results indicated that the optimal molding pressure and molding time were 3MPa and 5h respectively due to the fine interfacial bonding between fiber and matrix. The density of the SiC/SiC composites was 2.16g/cm3. The flexural strength and fracture toughness of the SiC/SiC composites were 637.5MPa and 29.8MPa·m1/2 respectively.

Failure Behaviour of High Toughness Multi-Layer Si3N4 and Si3N4-TiN Based Laminates

2005 ◽  
Vol 290 ◽  
pp. 175-182 ◽  
Author(s):  
Gurdial Blugan ◽  
Richard Dobedoe ◽  
I. Gee ◽  
Nina Orlovskaya ◽  
Jakob Kübler
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Residual Stresses ◽  
Crack Propagation ◽  
Failure Mechanisms ◽  
High Strength ◽  
Crack Deflection ◽  
High Toughness ◽  
Energy Absorbing ◽  
Crack Bifurcation

Multi-layer laminates were produced using alternating layers of Si3N4 and Si3N4+TiN. The differences in the coefficient of thermal expansions between the alternating layers lead to residual stresses after cooling. These are compressive in the Si3N4 layers and tensile in the Si3N4+TiN layers. The existence of these stresses in the laminates effect the crack propagation behaviour during failure. Different designs of laminates were produced with external layers under compression and tension exhibiting different failure mechanisms. Facture toughness was measured by SEVNB method. In systems with external layers under compression the measured fracture toughness was up to three times that of Si3N4, i.e. up to 17 MPa m1/2. In systems with external layers under tension during failure the energy absorbing effects of crack deflection and crack bifurcation were obtained. High temperature tests were performed to determine the onset temperature for residual stresses in these laminates. Micro-laminates with compressive layers of only 30 µm thickness with high strength and fracture toughness and were manufactured.

Microstructure and Properties of an Al-7.5Zn-1.5Mg-1.4Cu-0.12Zr Alloy Forging

2012 ◽  
Vol 706-709 ◽  
pp. 335-339 ◽  
Author(s):  
Xi Wu Li ◽  
Bai Qing Xiong ◽  
Yon Gan Zhang ◽  
Zhi Hui Li ◽  
Jiang Hai You ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Grain Morphology ◽  
High Strength ◽  
Thickness Direction ◽  
Microstructure And Properties ◽  
Good Corrosion Resistance ◽  
High Toughness ◽  
Precipitation Characteristics

In this present work, the microstructure and properties of an Al-7.5Zn-1.5Mg-1.4Cu-0.12Zr alloy forging in T7452 condition has been investigated by means of OM, TEM and EBSD analysis and varied properties test. The results indicate that there are obvious differences in grain morphology, precipitation characteristics and recrystallization degree along the thickness direction of the forging. The strength of the alloy forging is stable and varies less than 10% along the thickness direction. The alloy forging in the T7452 condition shows high strength, high toughness and good corrosion resistance, with the UTS, TYS, elongation and electrical conductivity values being 500~530 MPa, 460~500 MPa, 7.0~15.0% and 23.9~24.2 MS/m, respectively, and the fracture toughness in L-T, T-L and S-L direction being 33.5~39.5, 25.5~27.0, 23.0~24.5 MPa.m1/2, respectively, and the EXCO rating being EA.

Effect of Microstructure and Sintering Temperature on Fabrication of NITE-SiCf/SiC Composite

2007 ◽  
Vol 345-346 ◽  
pp. 1229-1232 ◽  
Author(s):  
Young Ju Lee ◽  
Han Ki Yoon
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Carbide ◽  
High Performance ◽  
Composite System ◽  
Matrix Composites ◽  
Practical Applications ◽  
Sic Fiber ◽  
Carbide Matrix ◽  
Sic Composites

Silicon carbide fiber-reinforced silicon carbide matrix composites (SiCf/SiC composites) are attractive materials for use in the blankets and divertors of fusion reactors due to their excellent thermo-mechanical properties and inherently low induced radioactivation. However, the brittle characteristics of SiC such as low fracture toughness and low strain-to fracture impose a severe limitation on the practical applications of SiC materials. SiCf/SiC composites can be considered as a promising candidate in various structural materials, because of their good fracture toughness. In this composite system, the direction of SiC fiber will give an effect to the mechanical properties such as fracture toughness and tensile strength. Therefore, it is important to control a proper direction of SiC fiber for the fabrication of high performance SiCf/SiC composites. .

CARPENTER TEMPER TOUGH ALLOY

Alloy Digest ◽  
2012 ◽  
Vol 61 (4) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Tensile Properties ◽  
High Strength ◽  
Heat Treating ◽  
High Toughness ◽  
Technology Corporation ◽  
Carpenter Technology Corporation ◽  
Quenched And Tempered Steel

Abstract Temper Tough alloy is an air-melted quenched and tempered steel with high strength and high toughness. This datasheet provides information on composition, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and machining. Filing Code: SA-650. Producer or source: Carpenter Technology Corporation.

DILLIMAX 550

Alloy Digest ◽  
2012 ◽  
Vol 61 (4) ◽  
Keyword(s):  
Fracture Toughness ◽  
Yield Strength ◽  
Physical Properties ◽  
Structural Steel ◽  
High Strength ◽  
Heat Treating ◽  
Bend Strength ◽  
Fine Grained ◽  
High Toughness ◽  
Minimum Yield

Abstract Dillimax 550 is a high-strength quenched and tempered, fine-grained structural steel with a minimum yield strength of 550 MPa (80 ksi). Plate is delivered in three qualities: basic, high toughness, and extra tough. This datasheet provides information on composition, physical properties, tensile properties, and bend strength as well as fracture toughness. It also includes information on forming, heat treating, and joining. Filing Code: SA-649. Producer or source: Dillinger Hütte GTS.

AVESTA SHEFFIELD 248 SV

Alloy Digest ◽  
1998 ◽  
Vol 47 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Martensitic Stainless Steel ◽  
High Strength ◽  
Heat Treating ◽  
High Toughness ◽  
Strength And Toughness

Abstract Avesta Sheffield 248 SV is a high-strength martensitic stainless steel. It combines high strength with good weldability and high toughness after welding. 248 SV is intended for applications that require high strength and toughness, good weldability, and moderate corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-725. Producer or source: Avesta Sheffield AB.

Sign in / Sign up

Export Citation Format

Share Document