Microstructure of intermetallic-matrix composites produced in situ by self-propagating high-temperature synthesis

1994 ◽  
Vol 52 ◽  
pp. 708-709
Author(s):  
C. P. Doğan ◽  
D. E. Alman
Keyword(s):  
High Temperature ◽  
Exothermic Reaction ◽  
Ceramic Composites ◽  
Matrix Composites ◽  
Temperature Synthesis ◽  
Intermetallic Matrix ◽  
High Temperature Synthesis ◽  
Wide Range ◽  
Intermetallic Matrix Composites

Self-propagating, high-temperature synthesis (SHS) is one method of material production in which elemental constituents are ignited, initiating a self-sustaining, exothermic reaction that results in their transformation into intermetallic and ceramic compounds. In addition, several reactions can be initiated within a single body to form intermetallic-intermetallic, intermetallic-ceramic, or ceramic-ceramic composites in situ. The driving force for the reactions is the negative heats of mixing of the forming compounds, which results in the liberation of heat. The obvious advantages of SHS processing are that it presents an opportunity to produce near net-shape advanced materials and composites with a high level of purity in a relatively low-cost and energy efficient manner.At the U.S. Bureau of Mines, we are actively involved in the SHS processing of a wide range of singlephase intermetallic and intermetallic-matrix composites: TiAl, TiAl+TiB2, TiAl+TiC, TiAl+Ti5Si3, MoSi2+SiC. One key element of our study is a thorough understanding of the effect of processing variables, such as composition, temperature, pressure, time, powder morphology, etc., on the microstructure, and hence the properties, of these materials.

Wear Behavior of SHS Intermetallic Matrix Composites

1994 ◽  
Vol 350 ◽  
Author(s):  
J. A. Hawk ◽  
D. E. Alman
Keyword(s):  
Wear Resistance ◽  
Volume Fraction ◽  
Wear Behavior ◽  
Matrix Composites ◽  
Temperature Synthesis ◽  
Intermetallic Matrix ◽  
High Temperature Synthesis ◽  
Abrasive Wear Behavior ◽  
Intermetallic Matrix Composites

AbstractA number of discontinuously reinforced, intermetallic matrix composites (i.e., TiAl/TiC, TiAl/TiB2, TiAl/Ti5Si3) were formed in situ through self-propagating, high-temperature synthesis (SHS) between elemental powders. This Bureau of Mines study characterizes the abrasive wear behavior of these composites. Wear behavior is discussed with respect to process history, and type and volume fraction of reinforcement. Generally, higher process temperatures lead to dense composites, resulting in better wear resistance. The wear behavior of the SHS intermetallic composites is compared to other intermetallics, produced by conventional techniques.

Self-Propagating High-Temperature Synthesis (SHS) of Advanced High-Temperature Ceramics

2008 ◽  
Vol 395 ◽  
pp. 15-38 ◽  
Author(s):  
Suman K. Mishra ◽  
Lokesh C. Pathak
Keyword(s):  
High Temperature ◽  
Ceramic Composites ◽  
Research Field ◽  
Advanced Materials ◽  
Temperature Synthesis ◽  
Advantages And Disadvantages ◽  
High Temperature Synthesis ◽  
Large Numbers ◽  
Material Preparation

Over the years, the self-propagating high-temperature synthesis (SHS) has become an interesting research field to prepare a large numbers of advanced materials. Recently, the demands for high temperature advanced ceramics have further intensified the research on SHS for efficient material preparation. Several reviews, large numbers of papers and patents on various aspects of material production by SHS are available in literature. These are scattered and it is desirable to have a comprehensive review of the literatures that not only helps the researchers but also guide the beginners in this area. In this paper, we have emphasized our contributions on synthesis of various advanced high temperature ceramics, the borides, carbides, oxides and their composites by SHS processes. Several advantages and disadvantages of the SHS technique for advanced high temperature (HT) materials are highlighted. The preparation of nano-sized powders and finegrained in-situ high temperature ceramic composites through SHS is specially mentioned.

Microstructural characterization of plasma-processed Ti-Al metal matrix composites

1989 ◽  
Vol 47 ◽  
pp. 552-553
Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
M. A. Burke
Keyword(s):  
High Temperature ◽  
Titanium Aluminide ◽  
Plasma Processing ◽  
Microstructural Characterization ◽  
High Temperature Strength ◽  
Matrix Composites ◽  
Intermetallic Matrix ◽  
Long Time ◽  
Strength And Stiffness ◽  
Intermetallic Matrix Composites

Intermetallic matrix composites are candidates for ultrahigh temperature service when light weight and high temperature strength and stiffness are required. Recent efforts to produce intermetallic matrix composites have focused on the titanium aluminide (TiAl) system with various ceramic reinforcements. In order to optimize the composition and processing of these composites it is necessary to evaluate the range of structures that can be produced in these materials and to identify the characteristics of the optimum structures. Normally, TiAl materials are difficult to process and, thus, examination of a suitable range of structures would not be feasible. However, plasma processing offers a novel method for producing composites from difficult to process component materials. By melting one or more of the component materials in a plasma and controlling deposition onto a cooled substrate, a range of structures can be produced and the method is highly suited to examining experimental composite systems. Moreover, because plasma processing involves rapid melting and very rapid cooling can be induced in the deposited composite, it is expected that processing method can avoid some of the problems, such as interfacial degradation, that are associated with the relatively long time, high temperature exposures that are induced by conventional processing methods.

The Mechanics and Mechanical Behavior of High-Temperature Intermetallic Matrix Composites

2000 ◽  
Author(s):  
Ronald Gibala ◽  
Amit K. Ghosh ◽  
David J. Srolovitz ◽  
John W. Holmes ◽  
Noboru Kikuchi
Keyword(s):  
High Temperature ◽  
Mechanical Behavior ◽  
Matrix Composites ◽  
Intermetallic Matrix ◽  
Intermetallic Matrix Composites

scholarly journals Intermetallic/Ceramic Composites Synthesized from Al–Ni–Ti Combustion with B4C Addition

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 873
Author(s):  
Chun-Liang Yeh ◽  
Chih-Yao Ke
Keyword(s):  
Combustion Velocity ◽  
Ceramic Composites ◽  
The Other ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
Reaction Systems ◽  
X Ray ◽  
High Temperature Synthesis ◽  
In Situ Formation

The fabrication of intermetallic/ceramic composites by combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) was investigated in the Al–Ni–Ti system with the addition of B4C. Two reaction systems were employed: one was used to produce the composites of xNiAl–2TiB2–TiC with x = 2–7, and the other was used to synthesize yNi3Al–2TiB2–TiC with y = 2–7. The reaction mechanism of the Al–Ni–Ti system was strongly influenced by the presence of B4C. The reaction of B4C with Ti was highly exothermic, so the reaction temperature and combustion velocity decreased due to increasing levels of Ni and Al in the reactant mixture. The activation energies of Ea = 110.6 and 172.1 kJ/mol were obtained for the fabrication of NiAl- and Ni3Al-based composites, respectively, by the SHS reaction. The XRD (X-ray diffraction) analysis showed an in situ formation of intermetallic (NiAl and Ni3Al) and ceramic phases (TiB2 and TiC) and confirmed no reactions taking place between Ti and Al or Ni. The microstructure of the product revealed large NiAl and Ni3Al grains and small TiB2 and TiC particles. With the addition of TiB2 and TiC, the hardness of NiAl and Ni3Al was considerably increased and the toughness was also improved.

scholarly journals Rapid Synthesis of Metallic Reinforced in Situ Intermetallic Composites in Ti-Al-Nb System via Resistive Sintering

2018 ◽  
Vol 16 (1) ◽  
pp. 869-875
Author(s):  
Mediha İpek ◽  
Tuba Yener ◽  
Gözde Ç. Efe ◽  
Ibrahim Altınsoy ◽  
Cuma Bindal ◽  
...  
Keyword(s):  
High Hardness ◽  
Processing Technique ◽  
Metallic Phase ◽  
Matrix Composites ◽  
Intermetallic Matrix ◽  
One Step ◽  
Intermetallic Matrix Composites ◽  
Hardness Values ◽  
A Current

AbstractIntermetallics are known as a group of materials that draws attention with their features such as ordered structure, high temperature resistance, high hardness and low density. In this paper, it is aimed to obtain intermetallic matrix composites and also to maintain some ductile Nb and Ti metallic phase by using 99.5% purity, 35-44 μm particle size titanium, niobium and aluminium powders in one step via recently developed powder metallurgy processing technique - Electric current activated/assisted sintering system (ECAS). In this way, metallic reinforced intermetallic matrix composites were produced. Dominant phases of TiAl3 and NbAl3 which were the first compounds formed between peritectic reaction of solid titanium, niobium and molten aluminum in Ti-Al-Nb system during 10, 30 and 90 s for 2000 A current and 1.5-2.0 voltage were detected by XRD and SEM-EDS analysis. Hardness values of the test samples were measured by Vickers indentation technique and it was detected that the hardnesses of intermetallic phases as 411 HVN whereas ductile metallic phase as 120 HVN.

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