Aims to synthesize Ti-Si thermal barrier coatings on Ti-6Al-4V alloy by laser additive manufacturing technique for applications such as turbine blades of an aircraft gas-turbine engine.

Titanium alloys exhibit poor tribological characteristic which include abrasion resistance, metal to metal wear resistance and solid particle erosion and cavitation due to low surface hardness and high coefficient of friction. These poor properties have limited the application of titanium alloys as engineering tribological components, tools and parts that operate in severe wear and friction conditions. Laser processing defects such as pores, cracks and segregation pose a huge threat to the quality and the microstructure of the deposited layer. Defects caused by the parameters lead to severe wear and corrosion occurrence, hence, precise control of the parameters are crucial and it depends on the properties of the material used. It is postulated that Nickel Titanium (NiTi) is a promising candidate as reinforcement matrix material for wear resistant alloy. The wear resistance would be further enhanced if NiTi is in-situ incorporated onto titanium matrix by laser cladding to yield hard intermetallic phases. The main goal of the study is to develop corrosive-wear resistant thin surface coatings on Ti-6Al-4V alloy for automotive and aerospace applications by depositing Titanium and Nickel elemental powders to form in-situ NiTi intermetallic using laser cladding technique.

This book provides scientific and technological insights on novel techniques of design and manufacturing using laser technologies. It showcases applications of laser micromachining in the biomedical industry, laser-based manufacturing processes in aerospace engineering, and high-precision laser-cutting in the home appliance sector. Features: Each chapter discusses a specific engineering problem and showcases its numerical, and experimental solution Provides scientific and technological insights on novel routes of design and manufacturing using laser technologies Synergizes exploration related to the various properties and functionalities through extensive theoretical and numerical modeling Highlights current issues, developments, and constraints in additive manufacturing Discusses applications of laser cutting machines in the manufacturing industry and laser micromachining for the biomedical industry The text discusses optical, and laser-based green manufacturing technologies and their application in diverse engineering fields including mechanical, electrical, biomedical, and computer. It further covers sustainability issues in laser-based manufacturing technologies and the development of laser-based ultra-precision manufacturing techniques. The text also discusses the use of artificial intelligence and machine learning in laser-based manufacturing techniques. It will serve as an ideal reference text for senior undergraduate, graduate students, and researchers in fields including mechanical engineering, aerospace engineering, manufacturing engineering, and production engineering.

Discusses the main objectives of this research: 1. Mathematical determination of the deposition velocity for successful cold spray coating of Ti-6Al-4V with SiC by the use of a constitutive equation to solve the momentum, continuity, and energy equations which govern fluid flow inside the de Lava nozzle used in the LPCS system. 2. Computational fluid dynamics (CFD) analysis of the flow of fluid in the nozzle to determine the inlet temperature that will produce the calculated velocity at the nozzle exit. 3. Mathematical determination of the optimum composition of the feedstock powder (silicon carbide, titanium and aluminium) using Scheffe’s (1958:344–366) simplex lattice theory and analysis of variance (ANOVA). 4. To develop a procedure for deposition of silicon carbide on Ti-6Al-4V using the cold spray technique which is usually not feasible because SiC is a ceramic powder and which is not amenable to plastic deformation. 5. To investigate the suitability of cermet powders (silicon carbide, titanium and aluminium) as feedstock powder for cold spray coating of Ti-6Al-4V. 6. To compare the properties of coating made with the optimised parameters with those of non-optimised parameters. 7. To study the improvements in the hardness and wear resistance of Ti-6Al-4V by cold spraying. 8. To compare the microstructure and properties of the coatings deposited on Ti-6Al-4V by cold spray and laser techniques.

Thermal barrier coating (TBC) systems are indispensable for utilization in gas turbine engines to decrease the thermal effect and enhance turbine efficiency by considerably raising applied gas temperatures. TBCs are typically composed of an underlying metallic bond coat known as MCrAlY (M=Ni, Co) acting as an oxidation resistant layer, and yttria-stabilized zirconia (YSZ) as a ceramic top coat that provides thermal insulation toward the metallic substrate. In this study Inter-metallic alloy based on Gamma Titanium Aluminide was chosen as a substrate due to its low density as compared to the conventional Nickel-based super alloy which made it competent to be an important structural material in high-temperature aerospace and automotive applications. TBC's bond coat and ceramic top coat were performed by EB-PVD at different partial pressures of Oxygen during deposition of the top layer in order to get deeper insight into the correlation between adhesion and deposition process parameters.

Titanium aluminides and titanium alloys are candidate materials for use in hot structure and heat-shield components of hypersonic vehicles because of their good strength-to-weight characteristics at elevated temperature. However, in order to utilize their maximum temperature capability, they must be coated to resist oxidation and to have a high total remittance. Also, surface catalysis for recombination of dissociated species in the aerodynamic boundary layer must be minimized. Very thin chemical vapor deposition (CVD) coatings are attractive candidates for this application because of durability and very light weight. To demonstrate this concept, coatings of boron-silicon and aluminum-boron-silicon compositions were applied to the titanium-aluminides alpha2 (Ti-14Al-21Nb), super-alpha2 (Ti-14Al-23-Nb-2V), and gamma (Ti-33Al-6Nb-1Ta) and to the titanium alloy beta-21S (Ti-15Mo-3Al-3Nb-0.2Si). Coated specimens of each alloy were subjected to a set of simulated hypersonic vehicle environmental tests to determine their properties of oxidation resistance, surface catalysis, radiative emittance, and thermal shock resistance. Surface catalysis results should be viewed as relative performance only of the several coating-alloy combinations tested under the specific environmental conditions of the LaRC Hypersonic Materials Environmental Test System (HYMETS) arc-plasma-heated hypersonic wind tunnel. Tests were also conducted to evaluate the hydrogen transport properties of the coatings and any effects of the coating processing itself on fatigue life of the base alloys. Results are presented for three types of coatings, which are as follows: (1) a single layer boron silicon coating, (2) a single layer aluminum-boron-silicon coating, and (3) a multilayer coating consisting of an aluminum-boron-silicon sublayer with a boron-silicon outer layer. Cunnington, George R. and Clark, Ronald K. and Robinson, John C. Langley Research Center ALUMINIDES; ENVIRONMENTAL TESTS; HYPERSONIC VEHI...