Abstract: A microturbine power generation system includes an electrical generator, a turbine and a compressor intermediate the generator and the turbine. Rotating components of the turbine, compressor and electrical generator are secured together by a tie-bolt. The tie-bolt is pre-stressed such that faces of the rotating components of the turbine, electrical generator and compressor maintain contact during high-speed, high-temperature operation of the system. The tie-bolt includes a thermally less conductive short portion that is secured to the rotating component of the turbine wheel, and an elongated portion that extends through the rotating components of the compressor and electrical generator. The short, thermally less conductive portion of the tie-bolt inhibits heat from propagating from the turbine end towards the compressor. The short, thermally less conductive portion can be a titanium rod that is inertia-welded between the elongated portion of the tie-bolt and the rotating component of the turbine.