Papers by Author: Chi Ping Lai

Abstract: This paper aims at presenting an experimental investigation to compare the rolling behaviors of selected materials under profile rolling process. Copper alloy (C37700), aluminum alloy (AA6063) and stainless steel (AISI304) in 6 mm diameter were selected as rolling specimens. The process parameters, i.e. spindle speed, forward speed, and fractorgraphic analysis were carried out to determine the deformation behaviours of selected materials. The outcomes of this investigation are valuable for engineers to design and fabricate high-quality precision components efficiently.

Abstract: This paper aims at presenting an experimental investigation to obtain the optimum formability of light-weight alloys under the multi-stage forming process. Titanium alloy sheets (Ti-6Al-4V) and aluminium alloy sheets (AA5052) are selected as forming specimens. The special fixture with heating device is applied in order to carry out the prestraining process. The swift forming test at warm-forming condition is performed for measuring the limit dome heights after the multi-stage formign process. The outcomes of this investigation are valuable for engineers to design and fabricate high-quality light-weight components efficiently.

Abstract: This paper aims to study the effect of stress relieving on Limit Dome Height (LDH) of Ti-TWBs at elevated temperatures. This is achieved by developing a newly constructed heating system. The elevated temperature of the system can be varied and monitored by a separately control panel. All Ti-TWBs were prepared and used to examine the LDHs under elevated temperatures. Selected specimens were heat-treated at 600°C within an hour before being formed by HILLE machine. Meanwhile, the temperature of tool heating system was also adjusted from room temperature to 550°C. Specified tests were carried out to examine the stress relieving effects of Ti-TWBs on the LDHs with the temperature control panel. In addition, investigations were carried out to ascertain whether the elevated temperatures of the critical tooling components, i.e. the die and the blank holder, could result in any significant effects on LDHs of Ti-TWBs. The findings show that LDHs of Ti-TWBs can be improved by stress relieving. The stress relieving condition can be obtained by nearly isothermal forming of specimens at a range of 550°C to 600°C.