Abstract: The aim of the present invention is a process for manufacturing boron nitride fibers, in particular continuous boron nitride fibers with good mechanical properties, which may be used for producing ceramic composite materials such as BN/BN composites, thermostructural parts or antenna radomes. It provides and uses a precursor polymer of formula (I) below: in which n is a whole number, R1 and R2, identical or different, represent independently an alkyl group, and R3 represents an amino group, a hydrogen atom, an alkyl, a cycloalkyl or a boryl.

Abstract: The pointed end of a central spike, used in an engine of a space launcher, may have a deformable structure that can adopt either a folded position or a deployed position.

Abstract: The temporary connection of two elements (12, 14) is ensured by U-shaped connecting components (16) held in place by a moving part (18). A pyrotechnic composition (20) is housed between two shoulders (32, 36) situated respectively on the first of the elements (12) and on the moving part. Igniting the pyrotechnic composition (20) causes the moving part (18) to slide over the first element (12). The connecting components (16) are released and the connection between the elements (12, 14) is eliminated without breaking any parts.

Abstract: The invention concerns a method for making boron nitride fibers by drawing a polymer precursor and treating with ceramics the polymer fibers obtained by drawing. The invention is characterized in that the precursor polymer is obtained by thermal polymerization of a borazine of formula (I) wherein: R1, R3, R4 and R5, identical or different, represent an alkyl, cycloalkyl or aryl group; and R2 represents a hydrogen atom or an alkyl, cycloalkyl or aryl group.

Abstract: The invention concerns a dome (34) consisting of a round-shaped vessel (30) provided with an opening (28) at the top and by a cap (33) welded on said basin to close said opening (28). The basin is obtained by hot forming under pressure of a truncated blank (5) made of non tempered aluminum alloy.

Abstract: A pyrotechnic actuator comprises a deformable membrane (24) separating a first chamber (20), which is able to receive pyrotechnic combustion gases, from a second chamber (22) containing a control member (32) displaceable by the membrane (24) during the operation of the actuator. In the inoperative state, the membrane (24) is prestressed counter to its deformation controlled by the intake of gases into the first chamber (20). In this way the functional travel is increased, which e.g. makes it possible to open or close a circuit with a larger cross-section without increasing the actuator size.