Numerical and Experimental Investigations on the Effects of Variable Cavity Pressure on the Formability of GLARE Using Hydromechanical Deep Drawing

Excellent physical and mechanical properties of fiber metal laminates (FMLs) have made them a very popular and most suitable material to make high strength and lightweight products in different industries for example automobile, military, and aerospace. Glass fiber aluminum reinforced epoxy (GLARE) is one of the most used fiber metal laminate among the family of fiber metal laminates, but there are some challenges in its formability. Our study mainly focuses on the formability of the GLARE cup parts by using hydromechanical deep drawing. Forming depth with good quality (without any wrinkling, delamination, or fracture), failure mode analysis and wall thinning rate (%) distribution of the parts are the main criteria in the formability. The influence of variable cavity pressure (VCP) with respect to punch strokes had been investigated by using numerical simulations and experiments. Results showed that the variable cavity pressure in case of increasing or decreasing the cavity pressure had very much effect on the formability. Stepwise increasing the VCP with respect to punch strokes resulted in a maximum forming depth of 29.00mm as well as good quality whereas in the case of stepwise decreasing the variable cavity pressure, results were not encouraging. Commercially available code ABAQUS explicit was used for finite element analysis simulation which had shown close agreement with the experimental results.

Investigation on the Effect of Type of Cooling on the Properties of Aluminum Alloy during Warm/Hot Hydromechanical Deep Drawing

The warm sheet cylindrical deep drawing experiment of aluminum alloy was carried out and macro-mechanical properties and microstructure evolution of hydro-formed cups with different cooling medium were analyzed, which aimed to investigate the effects of different types of cooling on mechanical properties and microstructure of cylindrical cups hydro-formed by warm Hydro-mechanical Deep Drawing (HDD). Results show that, under the condition of warm hydroforming, the mechanical properties such as yield stress and ultimate strength were influenced very little by air or water cooling. Grain coarsening of these hydro-formed cups can be inhibited to a certain extent with subsequent rapid water cooling. Moreover, it shows that the processing with warm sheet hydroforming and subsequent rapid cooling of 7075-O aluminum alloy has a positive significance in maintaining the stability of macro mechanical properties and inhibiting the degradation of the microstructure of materials.