Executive Summary : | With increasing challenges due to surface degradation by wear, corrosion and oxidation, most of the engineering components used in the power plants or aircraft industries face problems such as reduced performance and product design life. The demand for novel material capable of addressing many issues in a single go is the need of the hour. If we speak of boilers or gas turbines, the coating needs to have high-temperature erosion, corrosion and oxidation resistance. This is mainly because addressing anyone surface degradation type does not help challenge environments. It is well known that NiAl alloy possesses high-temperature properties. Still, the studies about their use as thermal spray coatings are not explored in detail, especially when NiAl is reinforced with hard phases like cBN and SiC. The NiAl, possesses an ordered crystal structure, low density, high melting point, high hardness, high mechanical strength, high-temperature corrosion and wear resistance. On the other hand, CBN and SiC particles are fundamental. They are known for their high melting point, low density, and extremely high hardness. They can exhibit high chemical resistance, good high-temperature strength, excellent thermal shock resistance, and excellent wear and abrasion resistance. These attributes are the perfect choice as a reinforcing phase for tackling surface degradation issues. So, this proposal focuses on developing novel NiAl composite coatings with CBN and SiC as reinforcing phases using HVAF and laser remelting techniques. The produced coatings could be used to protect boiler components in power plants or repair some aircraft components. The NiAl with CBN or SiC composite coatings will be using HVAF and laser remelting techniques. The main experiments that will be performed are high-temperature sliding wear, erosion and oxidation tests. How the addition of cBN and SiC will affect the high-temperature behaviour of NiAl composite coatings will be studied in detail. |