This work presents aspects related to new sintered materials for valve seat inserts application. Two types of materials were evaluated. The materials were made using powder metallurgy technique from a basic mixture of high-speed steel (AISI M3/2), iron and carbide powders. The microstructures of these materials before and after heat treatment are presented. Under the heat treatment condition, the activation of the diffusion mechanism among phases was promoted and a better distribution of the Cu phases along the matrix was achieved. The results indicate that the materials under development have a potential for commercial application as valve seat inserts.