Metal Forging Inspired Chain-Combing Processing Strategy for Engineering Plastic’s Properties Enhancement

This study presents a highly efficient Surface Mechanical Treatment (SMT) inspired by metal forging principles developed to significantly enhance the mechanical properties and surface durability of engineering plastics, including PA66, PEEK, POM, and PPS. Offering a sustainable and energy-efficient alternative to conventional polymer processing techniques, SMT achieves remarkable property enhancements. For example, when applied to PA66, SMT improved Young’s Modulus by 88.39% and Ultimate Tensile Strength (UTS) by 28.37%, while the surface layer demonstrated a 10-fold increase in modulus to approximately 10 GPa, accompanied by a 43.29% rise in Vickers Hardness and a 10% improvement in crystallinity. The methodology combines the application of compressive and shear forces via a custom-designed device with advanced molecular dynamics simulations, including force field molecular dynamics (FFMD) and ab initio molecular dynamics (AIMD). These simulations revealed a unique “chain-combing” mechanism, aligning polymer chains and reinforcing hydrogen bonding at the molecular level. Comprehensive structural analyses, such as SAXS and WAXS, further confirmed these findings by demonstrating enhanced crystallinity and the development of a pronounced surface-to-bulk property gradient. This research underscores the transformative potential of SMT as a surface-specific modification strategy, enabling substantial macroscopic property improvements through localized molecular restructuring. The findings open new avenues for processing engineering plastics, offering a pathway to developing more durable and efficient materials for industrial applications.