Thermal spray is a manufacturing process that are used to spray coatings onto various of structures. Thermal spraying can be done with different types of processes, this work focus on air plasma spraying. More precise, air plasma spraying of thermal barrier coatings. Thermal barrier coating is a material system commonly used in the heated sections of gas turbines.

The method of thermal barrier coatings is that they have a two-layered structure, topcoat and bondcoat. The purpose of the layers is to protect the components in the gas turbine in harsh thermal environments. The protection improves the efficiency and decrease unwanted emission.In air plasma spraying there are different gases that can be combined to achieve wanted surface properties. Plasma generation occurs within the plasma torch, where a gas mixture of example argon/hydrogen or argon/helium flows between the anode and cathode, undergoing ionization through an electrical arc dischargeGKN Aerospace Sweden manufactures components to aerospace industries, amongst gas turbines. The company consist of many different manufacturing processes, one of them is thermal spraying. At the thermal spray department in Trollhättan the experimental setup was carried out.

The report is researching if a replacement of helium in air plasma spraying of barrier coatings with hydrogen is possible. To determine if it is optional to use hydrogen instead of helium.