Abstract: A helmet for receiving a compatible visor comprises a shell and two guiding mechanisms. Each guiding mechanisms is located on a different side of the shell and is adapted to receive the compatible visor. The guiding mechanisms guide the compatible visor along a confined path extending from a retracted position, where the compatible visor is proximate a frontal portion of the shell and substantially outside a field of view of the wearer, to a deployed position where the compatible visor is substantially below a frontal lower edge and within the field of view of the wearer. The guiding mechanisms guide at least a lower portion of the compatible visor substantially towards a rear portion of the shell when the compatible visor is in the deployed position. The compatible visor has a lens, a face seal and one mounting interface on each side of the lens.

Abstract: The present document describes a composite material adapted to resist degradation by an erosive agent. The composite material comprises a steel base and crystals embedded in the steel base. At least 50% of the crystals have an elongated portion. Optionally, the composite material comprises an external surface for exposure to the erosive agent. At least 50% of the elongated portions are transverse to the external surface. A filler material is also described for forming the composite material on a ferrous surface by welding. The filler material comprises iron, carbon, boron, molybdenum and silicon. Methods are also described form forming the composite material.