Superhard TiB2 - Based Composites with Different Matrix Fabricated from Elemental Powders by SHS-p-HIP

2012 ◽  
Vol 77 ◽  
pp. 146-152 ◽  
Author(s):  
Marta Ziemnicka-Sylwester
Keyword(s):  
High Temperature ◽  
Hot Isostatic Pressing ◽  
Cutting Tools ◽  
Consolidation Process ◽  
Pressing Method ◽  
High Temperature Synthesis ◽  
Structural Applications ◽  
Improve Fracture Toughness ◽  
Ball Milling Technique ◽  
Main Component

TiB2is a superhard, high-temperature and high corrosion resistant material and it is under consideration for tungsten-free cutting tools and high temperature structural applications. Although such a covalent compound requires significantly elevated temperature for the consolidation, great exothermicity of TiB2synthesis by means of SHS (Self-propagating High-temperature Synthesis) can be “ïn situ” utilized. In this study, TiB2-based composites are fabricated from titanium, boron and binder metal. In order to optimize consolidation process and improve fracture toughness of the products, three types of binder, based on cobalt, nickel or copper were investigated. In respect to hardness, limited amount of binder, 5, 10 or 15 vol.% respectively, were applied; each time 5 vol.% of Ti addition for reaction with boron completeness was used. The TiB2based composites were fabricated from elements in one process by means of the SHS process combined with p-HIP (pseudo-hot isostatic pressing) method. The raw elemental powders were homogenized by wet mixing using ball milling technique. Dried mixtures were pressed into a compact, coiled by heating element and then exposed to the SHS-p-HIP process. After SHS initiation, the compact was pressed pseudo-isostatically under pressure of 190MPa for 5 min. The sintering additives and their concentrations significantly affected the consolidation process as well as the properties of composites. The highest hardness was obtained for samples sintered with cobalt, containing intermetallic binder. However, elemental metal binder was detected as a main component for samples sintered with copper. The relative density, SEM microstructure, phase composition and hardness are compared in this study.

Fabrication of AlN-SiC-TiB2 Ceramics by Self-Propagating High Temperature Synthesis and Hot Isostatic Pressing

2007 ◽  
Vol 546-549 ◽  
pp. 1505-1508 ◽  
Author(s):  
Li Juan Zhou ◽  
Yong Ting Zheng ◽  
Shan Yi Du ◽  
Hong Bo Li
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Combustion Product ◽  
Bending Strength ◽  
Hot Isostatic Pressing ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
Pressing Method ◽  
Isostatic Pressing ◽  
High Temperature Synthesis

The fabrication of AlN-SiC-TiB2 ceramics with powder mixtures of Al, 6H-SiC and TiB2 was investigated by self-propagating high temperature synthesis (SHS) and hot isostatic pressing (HIP). The powder mixtures were shaped by isostatic cool pressing method and the combustion reaction was carried at the pressure of 100-200 MPa N2 by an ignitor. The compositions and morphologies of the combustion product were studied by XRD and SEM. The determined bending strength and the fracture toughness of the ceramics were 350 MPa and 3.5 MPa⋅m1/2 respectively.

Isothermal Oxidation Behavior of AlN-TiB2 Ceramics Synthesized by SHS-HIP

2013 ◽  
Vol 575-576 ◽  
pp. 170-173
Author(s):  
Li Juan Zhou ◽  
Yun Xia Zhao ◽  
Hong Bo Li ◽  
Yong Ting Zheng ◽  
Fan Tao Meng
Keyword(s):  
High Temperature ◽  
Oxidation Behavior ◽  
Hot Isostatic Pressing ◽  
Isothermal Oxidation ◽  
Oxidation Products ◽  
Aluminum Borate ◽  
Temperature Synthesis ◽  
Good Oxidation Resistance ◽  
High Temperature Synthesis ◽  
Conductive Ceramics

sothermal oxidation behavior of the AlN-TiB2 conductive ceramics prepared by self-propagating high-temperature synthesis and hot isostatic pressing (SHS-HIP) was evaluated in a temperature range from 900 to 1400 °C for exposure times from 1 to 16 h in air. The oxidation experimental results show that the conductive ceramics have a good oxidation resistance below 1200 °C. The oxidation products on the sample surfaces are mainly composed of Al2TiO5, TiO2 and aluminum borate phases.

Fabrication of BN-AlN-TiB2 Compound Conductive Ceramics by Self-Propagating High Temperature Synthesis and Hot Isostatic Pressing

2007 ◽  
Vol 336-338 ◽  
pp. 786-789 ◽  
Author(s):  
Li Juan Zhou ◽  
Yong Ting Zheng ◽  
Shan Yi Du
Keyword(s):  
High Temperature ◽  
Composition Dependence ◽  
Bending Strength ◽  
Hot Isostatic Pressing ◽  
Microstructural Analysis ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
Isostatic Pressing ◽  
High Temperature Synthesis ◽  
Conductive Ceramics

BN-AlN-TiB2 compound conductive ceramics from powder mixtures of BN, Al, and TiB2 was fabricated by self-propagating high temperature synthesis (SHS) and hot isostatic pressing (HIP). The powder mixtures were shaped by isostatic cool pressing at 5-10MPa and the combustion reaction was carried at 100-200 MPa N2 by an ignitor. XRD experiments confirmed that the reaction was complete and only AlN, BN and TiB2 were detected. Optical microscopy as well as SEM with an electron probe microanalysis was used for microstructural analysis and revealed a relatively uniform distribution of particulates. The temperature-dependence and composition-dependence of the electrical resistivity of BN-AlN-TiB2 ceramics were studied. The results showed that the optimum composition was 5-10wt% BN, 30-55wt% Al and 60-40wt% TiB2, and the products had the density of 90% of the theoretical, resistivity of 80-1000 μ⋅cm and bending strength of 100-200 MPa.

Dynamic Compaction and Hot-Isostatic-Pressing of Nickelaluminides

1988 ◽  
Vol 133 ◽  
Author(s):  
O. Arkens ◽  
L. Delaey ◽  
J. de Tavernier ◽  
B. Huybrechts ◽  
L. Buekenhout ◽  
...  
Keyword(s):  
High Temperature ◽  
Hot Isostatic Pressing ◽  
Nickel Aluminides ◽  
Dynamic Compaction ◽  
Temperature Synthesis ◽  
Explosive Compaction ◽  
Isostatic Pressing ◽  
Fine Grained ◽  
High Temperature Synthesis ◽  
Fine Nickel

ABSTRACTExplosive compaction and HIPping of stoichiometric mixtures of Ni and Al (and B) powder is optimized in order to obtain fine grained NiAl− and Ni3Al(+B) intermetallics.Starting from an appropriate mixture of pure fine Ni− and fine Al− (and B) powders fine nickel-aluminides are produced due to a selfpropagation high temperature synthesis during processing. HIPping experiments are done also on spherical Ni-coated Al-powders. The specimens are characterized by metallography and the homogeneity of the final product is controlled by microanalytical methods.

Interface and mechanical behavior of MoSi2-based composites

1991 ◽  
Vol 6 (3) ◽  
pp. 505-513 ◽  
Author(s):  
J-M. Yang ◽  
S.M. Jeng
Keyword(s):  
High Temperature ◽  
Mechanical Behavior ◽  
Hot Pressing ◽  
Hot Isostatic Pressing ◽  
Interfacial Properties ◽  
Isostatic Pressing ◽  
Microstructural Parameters ◽  
Structural Applications

MoSi2-based composites reinforced with particles, whiskers, and continuous fibers were fabricated using hot pressing and hot isostatic pressing techniques. The microstructure, interface compatability, and interfacial properties between the reinforcements and matrix are discussed. The microstructural parameters which control the mechanical behavior of the MoSi2 composites were characterized. The need for developing a satisfactory reinforced MoSi2 composite for high-temperature structural applications is also addressed.

Synthesis and Properties of AlN-SiC-TiB2 Ceramics by SHS-HIP

2007 ◽  
Vol 353-358 ◽  
pp. 1517-1520 ◽  
Author(s):  
Li Juan Zhou ◽  
Yong Ting Zheng ◽  
Shan Yi Du
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Hot Isostatic Pressing ◽  
Temperature Synthesis ◽  
Powder Mixtures ◽  
Pressing Method ◽  
Maximum Value ◽  
High Temperature Synthesis

AlN-SiC-TiB2 ceramics were synthesized by self-propagating high temperature synthesis (SHS) and hot isostatic pressing (HIP) methods. The powder mixtures of Al, 6H-SiC and TiB2 were shaped by isostatic cool pressing method, and then combustion reaction was carried at the pressure of 100-200 MPa N2 by an ignitor. The solid solution of AlN and 2H-SiC in AlN-SiC-TiB2 ceramics was formed. The phase composition and microstructure were investigated by XRD and SEM. The mechanical properties of composite were measured as functions of composition. The maximum value of flexural strength and fracture toughness of composites were 430 MPa and 3.9 MPa⋅m1/2 respectively.

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