“…It is, in particular, a way of inducing solid state reactions at room temperature, of alloying elements with different melting points and of activating solids allowing, thus, reactions to take place at temperatures lower than usual. This technique was soon widely used to synthesize metal diborides, notably TiB 2 and ZrB 2 : -by high energy ball-milling of elemental powder mixtures followed or not followed by annealing treatments [12][13][14][15][16][17][18][19][20][21].…”