Advances in Combustion Synthesis and Technology

This paper describes a summary of the basis of the thermodynamic variables with their equations, the thermodynamic models with their equations, the thermodynamic modeling software with their databases, the thermodynamic background of the combustion synthesis (CS) process with some examples. The integral molar Gibbs free energy change of mixing (ΔG M ) is the most important thermodynamic quantity. There are several models to calculate and minimize ΔG M . The calculation of ΔG M can be very difficult if there are several components in the identified process. The thermodynamic computer packages (software and their databases) enable the calculation of complex equations with high accuracy. Adiabatic temperature (Tad) is one of the parameters essential for the self-propagation of combustion synthesis. The comparison of the most common thermodynamic modeling software was introduced in this study. The results of some of the experimental studies about the CS process were also given in the concept of this study.

Functionally graded materials (FGMs) are a new class of inhomogeneous composite materials that have attracted considerable attention in engineering applications. In these materials, there is a gradual change in properties along one dimension due to variation in chemical composition and/or structure. FGMs can be produced by a variety of methods such as electrodeposition methods, additive manufacturing techniques, chemical vapor deposition, and combustion synthesis or self-propagating, high-temperature synthesis (SHS). In this chapter, after a brief review of FGM materials and their production methods, the most recent and significant achievements in the combustion synthesis of FGMs are summarized. Studies indicate that this method is capable of fabricating high-performance FGM composites with engineered properties; however, research is still required for the improvement of product quality, e.g. by appropriate design of combination of materials and/or processes as well as finding low-cost, low-energy consolidation techniques. 

In the light of technological developments, the need for advanced ceramics and non-ferrous alloys is increasing day by day. Besides, the applications of nanotechnology to these areas for the production of materials with superior properties are in important research interest. Although there are many methods developed for the synthesis of nanoparticles of these materials, in recent years, the combustion synthesis method offers unique advantages in matters such as product properties, process control and cost. There are varying types of combustion synthesis and each type has been continuously developed recently and it could be seen that it is a method open to innovative developments. This chapter briefly discussed the basic principles, types, thermodynamic and kinetic basis of combustion synthesis. While doing this, both the approaches in the development of the methods were evaluated and examples from the studies carried out in recent years were given. Some studies on the basic parameters affecting the combustion synthesis method processes have been reviewed. It aims to give brief information about the materials that can be synthesized by this method. It aims to provide summary information transfer to those who will work on any combustion synthesis method and aim to help create a route for experimental study with the sample studies given. When the whole chapter is examined, it will be seen that the method of combustion synthesis offers great advantages for nanoparticle synthesis and makes it possible to produce a wide variety of materials with its many types.

Boron carbide creates a wide area of use thanks to superior hardness, high wear resistance, and melting temperature. In this study, the production parameters of this material and its various composites have been investigated by different methods. An effective two-stage production technology for nanocomposites based on boron carbide is suggested. First, boron carbide nanopowders are obtained by the combustion method, and then boron carbide based ceramic/metal-ceramic nanocomposites are produced by the joint sintering/milling/melting methods.

In recent years, the removal of pollutants from wastewater has been an important fact. There are several methods for the removal of pollutants such as photocatalysis, coagulation-flocculation, oxidation, membrane separation, etc. Adsorption is one of the methods that can be used for the removal of pollutants effectively. It is a low-cost and easily applicable method among removal methods. This chapter includes the adsorption properties of the composites synthesized via the volume combustion method. The studies which were carried out in recent years were reviewed. Synthesizing methods and adsorption properties were evaluated in detail and brief information was given. It is aimed to introduce a new methodology for using nano-size materials synthesized via the volume combustion method.

Shape memory alloys (SMAs) have become an important class of materials following the discovery of the shape memory effect (SME) in nitinol in 1963. The important properties of these alloys have paved the way for their use in various applications. Combustion synthesis has become an important production method because of its advantages. The production of SMAs by combustion synthesis is a subject that has been studied in recent years. The use of porous nitinol produced by this method in artificial bone implants has become a particularly remarkable issue in this area. In this section, information about SMAs and combustion synthesis will be shared, and then information about the studies conducted on the production of SMAs by combustion synthesis will be shared.

The need for biomaterials is increasing day by day and researchers and research groups are showing more interest in biomaterial production. Combustion synthesis is a production method that has been used for many years. Especially with the increase in the need for porous biomaterials, the production of biomaterials by combustion synthesis has also gained importance. Among the biomaterials used in the human body, calcium phosphate-based materials stand out due to their superior mechanical and chemical properties. Calcium phosphate-based biomaterials are used in both hard tissue and soft tissue replacements. It is possible to produce porous calcium phosphate-based biomaterials by the combustion synthesis method. On the other hand, it is possible to produce not only pure calcium phosphate-based materials but also their composites which are used in bone tissue engineering. In this chapter, the principles of combustion synthesis methods developed for calcium phosphate-based porous biomaterials are summarized. In addition, it is aimed to create a summary guide for experimental studies by presenting examples from the studies carried out in this field in recent years.

This paper describes a summary of the basis of high-entropy alloys (concept, physical metallurgy, properties, production routes, and application prospects) with some examples that indicate their production by combustion synthesis processes. High-entropy alloys (HEAs), are a relatively new group of alloys, have become one of the most interesting subjects among scientific studies due to their superior properties. The properties of HEAs are affected by their constituents and the production routes. Combustion synthesis is one of the production methods which is used to synthesize both high-entropy alloys and high-entropy compounds, such as oxides, carbides, etc. The results of some of the experimental studies about the CS process applied to the production of HEAs and their compounds were given in the concept of this study

The development of rare-earth phosphates synthesis and their application in optical devices is becoming a major area of research in recent past decades. Different soft-chemical routes have been adopted for the preparation of nanoscale materials. Recently, solution combustion synthesis has emerged as an extensive and earlier employed technique based on exothermic reactions along an aqueous or sol-gel media to produce nanophosphors. This chapter focus on the morphological and optical properties of rare earth monophosphates synthesized by the combustion route. The effects of chosen precursors, synthesis step, rare earth elements on structural, morphological, and optical properties of phosphors have been discussed based on X-ray diffraction, FTIR spectroscopy, Scanning electron microscopy images, photoluminescence excitation (PLE) and photoluminescence (PL), and the emission lifetime. The morphological and optical properties of rare earth monophosphate phosphors prepared by combustion technique are compared to those obtained by other methods.