Limit analysis on surface roughness and dimensional accuracy of spray metallic crust for rapid tooling production by metal arc spraying process

Abstract

Repetitively prototyping several prototypes of the same component using currently available rapidprototyping equipment can be very costly. Substantial savings can be attained with the use of a metal spray process to produce a crust shell on a rapid-prototyping pattern coated with mould release agent (PVA), and then backing the crust with aluminium granules so as to form rapid mould/tooling (RT). The smoothness of the innermost spray layer and its dimensional accuracy in relation to the RP prototype are factors that ensure good quality of parts replicated by RT. This paper establishes a preliminary model for predicting the upper bound of the former and the lower bound of the latter, which have been experimentally verified by arc spraying zinc onto PVA. The theoretical model permits the prediction of spraying parameters for controlling the achievable surface finishing and dimensional accuracy of a spray in RT production.

Structural analysis on the arc spraying rapid tooling for sheet forming

“…For example, the influences of process variables [13,14], the substrate thermal conditions [15], the phase formation [16], and the transient heat transfer were researched [17]. An automated ASRT system was developed for rapid die making of large-sized automobile body panels [18].…”

Poly(vinyl alcohol) as a structure release layer for the microfabrication of polymer composite structures

“…PVA has traditionally been used in industry as a mold release agent [24][25][26]. It also has applications in drug delivery and, because of its biocompatibility, it has been used in conjunction with extra-cellular matrix proteins as a tissue scaffold [27,28].…”