Rifai, M. ., Mujamilah, M., Insani, A. ., Muslih, M. R. ., Priyanto, T. H. ., Sumirat, I. ., Bharoto, B., Sulungbudi, G. T. ., Prasetya, A. D. ., Ridwan, R., Saparudin, M. ., Noor H., D. ., Sairun, S., Apriansyah, R. ., & Lubis, W. Z. . (2026). Exploring the Impact of Deformation on Strain Energy of Ultrafine-Grained Copper through Equal Channel Angular Pressing: Insights from X-Ray and Neutron Diffraction. Journal of Mathematical and Fundamental Sciences, 57(3), 221-236. https://doi.org/10.5614/j.math.fund.sci.2026.57.3.4