Experimental and theoretical study on minimum achievable foil thickness during asymmetric rolling

Area of Science:

• Materials Science
• Manufacturing Engineering
• Mechanical Engineering

Background:

• Microforming and micro-machines demand increasingly thinner foils.
• Asymmetric rolling offers potential for thinner foils than conventional rolling.
• The role of the cross-shear zone in asymmetric rolling's minimum thickness is not fully understood.

Purpose of the Study:

• To investigate the influence of the cross-shear zone on minimum achievable foil thickness in asymmetric rolling.
• To correlate asymmetric rolling parameters with minimum foil thickness.
• To develop a predictive formula for minimum foil thickness.

Main Methods:

• Experimental investigation of asymmetric rolling.
• Varying the rolling speed ratio to analyze cross-shear effects.
• Data analysis to establish correlations and derive a formula.

Main Results:

• Asymmetric rolling with a speed ratio of 1.3 achieved foil thicknesses approximately 30% of conventional rolling.
• Minimum achievable thickness was correlated with the cross-shear ratio and rolling speed ratio.
• A formula was developed to calculate minimum achievable thickness based on cross-shear ratio, friction, and roll radius.

Conclusions:

• The cross-shear zone is a critical factor in achieving ultra-thin foils via asymmetric rolling.
• The developed formula provides a method to predict and optimize minimum foil thickness.
• This research advances the capability of producing ultra-thin foils for micro-scale applications.