1. Use a maul or splitting wedges to split hardwood. A splitting maul is essentially a thicker, more wedge-shaped axe made for splitting hardwood along the grain, with a blunt sledge-hammer edge on the back of the splitting blade.
Carbon fibre is a material that is made from very thin fibres having carbon atoms. These are bonded together in microscopic crystals, aligned parallel to the long axis of the fibre. It is this crystal alignment that makes carbon fibre so strong. Carbon fibre is used to make composite materials with plastics resins.
Adding carbon to iron to make steel does make it stronger and tougher, up to a point. Then it will get stronger but less tough (ie like cast iron). Carbon strengthens iron by distorting its crystal latice. This distortion is similar in effect to work hardening. It is unfortunately a very complex effect and depends on how the steel is heat treated and exactly what percentage of carbon is added (<4% by wieght normally). It is not true of all metals.