Formability and densification behavior of two-layered structure powder metallurgical hot-pressed Al-Cu/Al composites during hot-upsetting. (April 2021)

• Record Type: Journal Article
• Authors: Rajasekhar, Kotikala; Babu, V Suresh; Davidson, MJ; Raghavendra, G
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 235:Number 2(2021)
• Page Start: 582
• Page End: 593
• Publication Date: 2021-04
• Subjects: Powder metallurgy -- hot-upsetting -- formability -- densification; Mechanical engineering -- Periodicals; Production engineering -- Periodicals; Manufacturing processes -- Periodicals; 621.05
• DOI: 10.1177/0954408920971974
• Languages: English
• ISSNs: 0954-4089

Abstract

An experimental investigation has been performed on the hot formability and densification characteristics of Al-Cu/Al two-layered structure composites. The two-layered composites having different Cu compositions in the Al-Cu layer such as (Cu: 5wt. %, 10wt. %, and 15wt. %) were prepared using the powder metallurgy (P/M) route. The composites were hot-pressed as layer by layer in a steel cylindrical die at 550°C temperature with 0.9 initial relative density (IRD) and 0.1 s −1 strain rate. The preforms were hot deformed between two flat dies with a capacity of 50-ton hydraulic press machine at a temperature range of 150°C – 450°C under triaxial stress state condition. The hot-upsetting behaviour of preforms was analyzed until the cracks begin on the cylindrical preform at the outer surface. The effect of different Cu composition and various deformation temperatures on two-layered preforms were discussed. Results revealed that the (10wt. %Cu) preform achieved good cooperative deformation behaviour between Al-Cu and Al layers at the interface region. The relationship between the process parameters was discussed such as the effect of axial stress (σ z ), relative density ( R ) on axial strain (ε z ) and formability stress index ( β ), different stress ratio parameters (σ θ / σ eff, σ m / σ eff ) on relative density ( R ).