(A) study on rapid manufacturing process and applications by high-speed machining with automatic filling

Abstract

Since its birth in the late 1980s, Rapid Prototyping and Manufacturing (RPM) technology has played a crucial role to innovate the product development process across the various fields of industry. Rapid prototyping (RP) processes using non-functional materials, such as photopolymer, plastics, paper, etc., have been well established so that they could even produce parts in production quality directly from the CAD solid data. In addition, they can create precise and strong models to be used as master patterns for tooling applications; however, the intermediate conversion process in between unavoidably requires additional building time and cost. Thus, as an attempt to minimize the additional efforts, a new category of RP processes using metals have emerged to fabricate metal parts and moulds directly from the CAD data. Metal RP processes based on metal deposition build layers by depositing molten metal. The metal deposition methods include laser sintering, laser cladding, welding and so forth. Due to the nature of layer-by-layer building processes and the thermal deformation during solidification, however, the resulting surface quality and dimensional accuracy are inherently limited. Also, Compared with conventional CNC machining, high-speed machining (HSM) technology has several advantages. It was reported that with HSM, due to its high material removal rate, aluminum alloys could be machined ten times faster than with CNC machining. Furthermore, most of the heat generated during machining is carried away by chips so fast that the part temperature remains almost unchanged, nearly no thermal effects on part properties. And these strengths unarguably make HSM a promising rapid manufacturing (RM) technology. However, HSM is capable of generating only embossed surfaces, i.e., it cannot be applied to the fabrication of three-dimensional parts with geometrical complexity including reentant cavities; and also the workpiece set-up is time-consuming and occupies a large...