of the joining contour of the heat shield in this regard reference is made to the exemplary embodiment described in the figures fig1 a shows a partial view of a longitudinal section through a heat shield 103 in the region of the joining contour 108 which issues into a corresponding groove shaped reception contour 110 of an axially adjacent root of a guide vane 101 u2032 the axial depth of the reception contour 110 is dimensioned in such a way that in the case of a thermally induced material expansion of the heat shield 103 the joining contour 108 is mounted slideably along the axially oriented clearance 111 the joining contour 108 consequently executes a translational movement indicated by the direction of the arrow e u2032 in the exemplary embodiment illustrated in fig1 a the joining contour 108 has a radially outer joining face 116 in which a groove shaped recess 114 is incorporated the depth of the groove shaped recess 114 measured from the joining face 116 corresponds at least to the maximum radial extent of the seal 112 the shape of which is adapted to the inner contour of the groove shaped recess 114 so that the seal 112 can be pushed completely into the recess 114 furthermore within the groove shaped recess 114 a spring element 118 is provided which is introduced between the groove bottom of the recess 114 and the seal 112 so that the spring element 118 can drive the seal 112 radially upward for a supplementary overview of the design of the seal 112 of the spring element 118 and of the groove shaped recess 114 within the joining contour 108 reference is made to.