Greener manufacturing: Superplastic-like forming

Abstract

Conventional superplastic forming (SPF) is normally conducted at a slow forming rate (10−3 s−1 or slower) and high temperatures (typically 773 K or higher for aluminum alloys), which is not attractive for wider applications. Recently, SPF has revived as an attractive process in the automotive and aerospace industries, especially for forming of excellent precision, large, and complex-shaped work pieces. A hybrid superplastic forming process has exploited the usage of superplastic forming for faster times, lower temperatures, and also for use by non-superplastic materials by designing a process that combines stamping and gas blow forming in one operation to establish an energy-saving technology. With recent developments in these areas, the light-weight, yet inexpensive aluminum alloys are promising candidates for green manufacturing. In comparison with the conventional SPF process, the forming time has been shortened (typically from 30 min to 8 min), and the forming temperature has been lowered down (from 773 K to 673 K). Furthermore, as a greener manufacturing process, it uses the non-superplastic grade materials, which is more compatible with existing manufacturing processes with less material preparation time and expense cost.