"The main objective of this research work was to produce environmentally friendly cermets coatings, Ni and Co free matrix, alternative to conventional WC- Co, by thermal spray processes. WC-Co cermets has always been one of the most on demand coatings in anti-wear and anti-corrosion applications in industry but environmental problems caused by heavy metals matrix (Co and Ni) force the redesign of many conventional processes. These elements are not harmful in their fundamental state, but processing generate changes in oxidation states that make them carcinogenic and mutagenic. For this reason, this research has focused on either replacing the existing processes or use raw materials that are less harmful. Therefore depositing the green carbides cermets onto the different substrates by conventional or novel (CGS) techniques are the main motivation points of this thesis. No one has previously successfully deposited such material by CGS or HVOF method with the same properties as the conventional WC-Co which was also one of the main motivation points. In this work we could produce Ti-TiC coatings with different percentage of Carbide phase by CGS, TiC-based with FeCrAlTi metal matrix by HVOF method, SiC-based cermets with Ti and TiCr metal matrixes by both CGS and HVOF technique and WC-based cermet with Ti metal matrix by CGS, HVOF and APS techniques. For this reason the main objectives of this Thesis entitled "Deposition of green carbide cermets coatings by thermal spray techniques". GLOBAL TREND FOR TIC SYSTEM: For all three Ti-TiC powders by increasing the SOD from 20 to 40, hardness has been increased which can be related to the decreasing the porosity of produced coatings by increasing the carbide phase which can be observed at SEM micrographs. The Higher adhesion strength of coating related to Ti-65%TiC can be explained by higher amount of hard carbide phase. When powder impact the substrate, powder with higher amount of hard phase deforms the substrate more and immerge the substrate deeper and as a result stronger mechanical bonding between the coating and substrate will be happened. From the wear rate comparison of obtained coatings regarding different Ti-TiC cermets can be resulted that Ti-65%TiC showed better wear resistance properties because of higher hardness and lower porosity. The optimal coating for Ti-TiC system was obtained at medium pressure and medium-high temperature related to Ti- 65%TiC and by increasing the temperature, there was an erosion and the coating was brittle and fully cracked. At high pressure and high temperature there was no deposition at all. Obtained coating related to TiC-FeCrAlTi by HVOF showed relatively good microstructural and mechanical properties. GLOBAL TREND FOR SIC SYSTEM: For this system there was no significant difference between microstructural properties of obtained coatings related to both powders by CGS method, both coatings had a hardness of about 500 HV. Though in order to improve the microstructural properties of coating related to Ti-SiC especially the hardness, coating went through the thermal treatment (annealing at 750°C). The microstructure of the coating was significantly changed because the interfaces between the deposited powder particles tended to disappear and a stronger metallurgical bond was formed [61–63]. HVOF coating of Ti-SiC presented higher hardness value than CGS mainly because of decomposition of Ti-SiC powder during the process and therefore hardening effect of SiO2 phase. Besides a higher hardness, HVOF coating was more brittle (less fracture toughness value) than CGS coating due to the lower content in elemental ductile Ti matrix and the presence of fragile and hard SiO2 phase formed during the HVOF spraying process. The lower value of fracture toughness in HVOF coating can be also attributed to the fact that during CGS the powder is not subjected to phase changes and no draining of the ductile free metallic matrix in the microstructure happens. The Ti present in the coating is kept and acts as a ductile element hence improving the fracture toughness of the CGS coating. Wear rate comparison of formed coatings related to Ti-SiC by CGS and HVOF using Propylene was shown in previous chapter, significantly lower wear rate of cold sprayed coating of Ti- SiC than HVOF can be explained by higher fracture toughness value of obtained coatings by CGS despite of higher hardness value of obtained coating by HVOF. Wear rate comparison of formed coating related to TiCr-SiC by HVOF and using H2 and Ti-SiC by HVOF and using Propylene showed that coating related to TiCr- SiC had better wear resistance than Ti-SiC because of less formed porosity in coating especially on top of the coating which was in contact with rubber wheel also from the results of fracture toughness of coatings can be explained that coating from TiCr-SiC had more fracture toughness value than the one from Ti- SiC by HVOF. GLOBAL TREND FOR WC SYSTEM: Ti-WC (400HV) was deposited onto the carbon steel substrate by HVOF and a coating with hardness of almost 900 HV was obtained. The produced coating by using Propylene had higher hardness than the one produced by using H2 though the thickness of coating for both coatings was not thick enough. This powder was sprayed onto the carbon steel substrate with a bond coat layer of Titanium by CGS in order to increase the adhesion between the powder particles and the substrate surface and after obtaining the coating the sample went through the post thermal treatment (HT Temperature: 650°C, HT isotherm: 60 mins, Ramp: 5 (°C/min), Atmosphere: Vacuum) in order to increase the hardness of the coating. After HT, hardness of coating reached a value of 1200 HV from 750 which was considerable. The higher hardness of HVOF Ti-WC than CGS can be explained because of decarburization of WC particles during HVOF, as the particles are exposed to hot and usually Oxygen rich environment. As a result, W2C and depending on the processing conditions even W is formed as well as volatile CO and CO2. From Ti-WC (650HV) and (1500 HV) powders the coatings were produced by APS technique though they were so porous. CONCLUSIONS: From this study following findings can be resulted: 1.Green cermets coatings with different metallic matrix (Ti, FeCrAlTi) and different carbides (TiC, SiC, WC) have been produced successfully by different thermal spray techniques and can be used as alternative to WC- Co or Cr3C2-NiCr for anti-wear applications. Because of the high density of WC-Co and Cr3C2-NiCr coatings in applications where command reduction in weight is needed and its high relative cost as compared to TiC based hard metals and hazardous nature of Cobalt and Nickel matrix, green cermet coatings can be good alternatives in the bench market. 2.In CGS method has been observed a trend which by increasing the temperature to the max and increasing the pressure, visible cracks in deposited particles, weak bonding in central area of splats-substrate interface, less penetration and less plastic deformation have been observed. This trend can be explained by impact velocity of the particles which has been increased by increasing the spraying temperature and pressure till the critical value (the optimal condition) and afterward the excessive particle velocities has been resulted erosion and avoiding a proper deposition process. Spraying pressure and temperature both had the direct relation with the impact velocity of particles though increasing the pressure affected the impact velocity of particles more than the temperature. This phenomena has led to a decrease in hardness value and fracture toughness of produced coatings. The optimal parameters have been set at intermediate temperatures and pressures. 3.In HVOF there was no significant difference between mechanical properties of the coatings by using hydrogen and propylene as fuel gases. Though for each system, produced coatings by using Propylene as fuel gas had slightly higher hardness value and lower wear rate which was considered as the optimum coating by HVOF for each system. 4.In general HVOF has produced coatings with presence of continues oxide phases network and lower content in elemental ductile metal matrix which as a result higher hardness and lower fracture toughness has been achieved. In contrast CGS has produced coatings with absence of fragile oxide phases which has led to the higher fracture toughness but lower hardness value. In CGS the hard carbide phase was not melted and was not distributed in metallic matrix homogenously and that is why it has lower value of hardness against HVOF coatings. The optimum coating of this study which can be considered as the alternative to WC-Co or Cr3C2-NiCr for anti-wear applications was Ti-WC by CGS after a post heat treatment. This coating reached the significantly enhanced microstructural properties due to the release of residual stress during the thermal treatment and hardness value of 1200 HV with significantly low wear rate." -- TDX.

This book provides the latest information about the research being conducted and established solutions available in the field of thermal spray coatings for various engineering applications. The readers of this book will be mainly the graduates, engineers and researchers who are pursuing their carrier in the field of thermal spraying. This book will cover the studies and research works of reputed scientists and engineers who have developed thermal spray coatings for thermal protection, bio-implants, renewal energy, wear and corrosion in hydraulic turbines and jet engines, hydrophobic surfaces etc. Hence, the book serves as a valuable resource of latest advancement in thermal spray technology and consolidated references for aspirants and professionals of surface engineering community. The book covers following topics for different industrial applications: Introduction: Historical developments, Science and Engineering aspects of thermal spray coating technology and different thermal spray coatings techniques and its comparison with other fabrication processes. Recent advancements and applications of thermal spray coatings Cold spray technology for additive manufacturing. High-temperature corrosion and erosion resistant coatings and thermal barrier coatings for power plants, automotive sector, and jet engines. Erosion and corrosion-resistant coatings for hydro-power plants, offshore, chemical and oil industries. Bio-coatings for human body implants. Thermal spray coating for super-hydrophobic surface. 3. Case study of boiler tubes failure and prevention by thermal spray coatings.

The cold spray process produces dense, low oxide coatings which can be used in such diverse applications as corrosion control and metals repair. It has emerged as an important alternative to thermal spray coating techniques in certain areas. This pioneering book reviews both the fundamentals of the process and how it can best be applied in practice. The first part of the book discusses the development of the process together with its advantages and disadvantages in comparison with thermal spray coating techniques. Part two reviews key process parameters such as powders, nozzle design, particle temperature and velocity, and particle/substrate interaction. It also describes portable and stationary cold spray systems. The final part of the book discusses how the cold spray process can be applied in such areas as improved wear, corrosion protection, electromagnetic interference shielding and repair of damaged components. The cold spray materials deposition process is a standard reference on this important process and its industrial applications. Examines the fundamentals of the cold spraying process Assesses how the technique can best be applied in practice Describes portable and stationary cold spray systems

Advanced Nanomaterials and Coatings by Thermal Spray focuses on the design, preparation, characterization and application of advanced coating materials for promising industries via thermal spray. Chapters introduce the potential applications of advanced nanocoating materials, the unique characteristics of thermal sprayed nanocoating, the design and processing of nanopowders, and discuss various nanocoating materials and their microstructure/properties. In addition, nanomaterials with unique characteristics are presented, i.e., the dendrite or feather-like nanomaterials by suspension spray or plasma spray-physical vapor deposition hybrid technology. This book will serve as an excellent resource for both researchers and individuals in industry. - Provides a comprehensive overview of the field of advanced nanocoatings materials and the use of thermal spray methods - Discusses the connections between the design, preparation, characteristics and applications of thermal spray nanocoatings - Reviews the properties and potential application of nanocoating materials, providing professionals with a guide on which nanocoatings have potential for their detailed requirements and development choices

This reference covers principles, processes, types of coatings, applications, performance, and testing and analysis of thermal spray technology. It will serve as an introduction and guide for those new to thermal spray, and as a reference for specifiers and users of thermal spray coatings and thermal spray experts. Coverage encompasses basics of th

Organized in a clear and logical format, it provides a complete description of thermal spray coatings' technology. Discusses the most important techniques in present use as well as those in research and developmental stages. Correlates coatings' properties with their microstructure and processing parameters. Outlines methods of post-spraying treatments including mechanical finishing, high pressure, high temperature and laser.

Thermal spraying is a dynamic process and a rapidly changing field which is used in a variety of industries to solve a number of challenging problems including performance enhancement and extending the life of industrial components which are subjected to wear corrosion. Thermal Sprayed Coatings and their Tribological Performances showcases the latest research surrounding the development and use of thermal spraying techniques as well as the benefits of using thermal sprayed coatings in the industrial sector. Focusing on practical solutions that can be applied to real-world settings, this publication is ideally designed for academicians, upper-level students, as well as engineers and operations managers across industries.

This book combines the contributions of experts in the field to describe the behavior of various materials, micromechanisms involved during processing, and the optimization of cold-spray technology. It spans production, characterization, and applications including wear resistance, fatigue, life improvement, thermal barriers, crack repair, and biological applications. Cold spray is an innovative coating technology based on the kinetic energy gained by particles sprayed at very high pressures. While the technique was developed in the 1990s, industrial and scientific interest in this technology has grown vastly in the last ten years. Recently, many interesting applications have been associated with cold-sprayed coatings, including wear resistance, fatigue life improvement, thermal barriers, biological applications, and crack repair. However, many fundamental aspects require clarification and description.

Future Development of Thermal Spray Coatings discusses the latest developments and research trends in the thermal spray industry. The book presents a timely guide to new applications and techniques. After an introduction to thermal spray coatings by the editor, Part One covers new types and properties of thermal spray coatings. Chapters look at feedstock suspensions and solutions, the application of solution precursor spray techniques to obtain ceramic films and coatings, cold spray techniques and warm spray technology amongst others. Part Two of the book moves on to discuss new applications for thermal spray coatings such as the use of thermal spray coatings in environmental barrier coatings, thermal spray coatings in renewable energy applications and manufacturing engineering in thermal spray technologies by advanced robot systems and process kinematics. - Timely guide on the current advancements and research trends in thermal spray technology - Reviews different types of thermal spray coatings - Presents a wide variety of applications for this emerging technology