Device and method to improve as-cast inner surface quality in cast parts

A flexible grinder device, comprising:

• a hydraulic motor powered by a fluid including at least one of air or water;
• a control module in communication with the hydraulic motor;
• a flexible pressure vessel coupled to the hydraulic motor, wherein the flexible pressure vessel is configured to contain the fluid, wherein the fluid is configured to be pressurized, wherein the flexible pressure vessel is rotatable by the hydraulic motor, wherein the flexible pressure vessel is conformable with an as-cast inner hole surface, and wherein the flexible pressure vessel is configured to withstand a pressure between 10 and 50 pounds per square inch (psi);
• and
• an abrasive layer coupled to an outer surface of the flexible pressure vessel, wherein the abrasive layer includes abrasive particles formed from at least one of aluminum oxide (Al2O3) or silicon carbide (SiC).

A method for cleaning an as-cast inner hole surface using a flexible grinder device, comprising:

• ushering a flexible pressure vessel of the flexible grinder device into an as-cast inner hole, wherein the flexible pressure vessel is mechanically and fluidly coupled to a hydraulic motor powered by a fluid;
• pressurizing the flexible pressure vessel with the fluid so that the flexible pressure vessel flexibly conforms to the as-cast inner hole surface;
• and
• rotating the flexible pressure vessel using the hydraulic motor, wherein an abrasive layer disposed on an outer surface of the flexible pressure vessel cleans the as-cast inner hole surface as the flexible pressure vessel rotates.