Linear friction welding is a solid state joining process used in the aerospace industry to join titanium and other high strength alloy blades in high performance aircraft engines. It is a variant of friction welding, which is a family of processes based on the frictional heat which develops due to the relative movement between two components. They are different from conventional fusion welding as they do not form a molten pool of material at the joint. The seminar will focus on the various modeling techniques (analytical, numerical, process, etc.) used to address individual phases of the process. It will present research work on the beginning of the process, where friction plays a dominant role, till after the relative movement of the parts stops and a joint forms, where residual stresses developed in the weld affect design decisions and the component’s service life.