We prove that any non commutative polynomial of r independent copies of
Wigner matrices converges a.s. towards the polynomial of r free semicircular
variables in operator norm. This result extends a previous work of Haagerup and
Thorbjornsen where GUE matrices are considered, as well as the classical
asymptotic freeness for Wigner matrices (i.e. convergence of the moments)
proved by Dykema. We also study the Wishart case