Forming an article made of metal matrix composite

An article made of a metal matrix composite material having particles bonded to an anodizable matrix material and having a machined surface comprising a portion of an anodic layer and a portion of the anodizable matrix material, the article having a heat dissipating substrate and being prepared by a process comprising the steps of:

• anodizing the anodizable matrix material to form an anodic layer on the anodizable matrix material;
• machining at least a portion of the anodic layer to provide the machined surface comprising a portion of the anodic layer and a portion of the anodizable matrix material;
• removing at least a portion of the anodic layer after machining to expose at least a portion of the particles that are intact and bonded to the anodizable matrix material;
• inspecting the article to determine whether the article is within a pre-determined tolerance;
• and
• repeating at least the anodizing, machining, and inspecting steps until the article is within the pre-determined tolerance;
• wherein the particles comprise diamond particles with beta-SiC chemically bonded thereto.