Electrochemical machining (ECM) is one of the important machining processes for machining alloys and composites. Aluminum metal matrix composites (AMMCs) are increasingly gaining in importance in the aerospace and automobiles industries. In this research the metal matrix composite (MMCs) is fabricated using the aluminum alloy (7075) with 5 % mass fraction of B4C and 10 % mass fraction of B<inf>4</inf>C in two different proportions as reinforcement. AMMCs (Al7075 with 5 % mass fraction of B<inf>4</inf>C and Al7075 with 10 % mass fraction of B<inf>4</inf>C) specimens were fabricated through a stir-casting process. The comparative study of the machinability of these composites is proposed using ECM. The input parameters like electrolyte temperature, electrolyte concentration, voltage and duty cycle were chosen and machining speed, overcut and delamination factor (DF) are considered as an output response. Sodium nitrate is used as an electrolyte and the electrolyte is heated by an induction heater to maintain the temperature during the machining, which was monitored continuously with a thermocouple. Based on conducted experiments the machining speed increases with the electrolyte temperature. The specimen of Al7075 with 10 % mass fraction of B<inf>4</inf>C composite shows a lower overcut and DF during the ECM process. Based on a Scanning Electron Microscope (SEM) image it is evident that the proper circular holes were obtained on the AMMC specimens (Al7075 with 5 % mass fraction of B<inf>4</inf>C and Al7075 with 10 % mass fraction of B<inf>4</inf>C). The EDAX analysis and Rockwell hardness test were performed to study the mechanical properties of the specimen. © 2020 Elsevier B.V., All rights reserved.