Powder metal process for preparing computer disk substrates

摘要

A method is provided for preparing computer disk substrates having low surface amplitude which comprises: (a) forming a liquid suspension containing aluminum powder, an aluminum alloying element and a borate composition by initially admixing the borate composition with a volatile liquid medium to obtain a borate solution and thereafter admixing the aluminum powder and aluminum alloying element with the borate solution to produce the liquid suspension; (b) heating the liquid suspension to remove the liquid medium and to obtain a dry aluminum powder composition; (c) isostatically pressurizing the dry aluminum powder composition and roller compacting the same into sheet form; (d) heating and sintering the sheet form in a non-oxidizing atmosphere; and (e) cutting and compressing the sintered sheet into computer disk substrate configuration.