Metal Forging Inspired\nChain-Combing Processing Strategy\nfor Engineering Plastic’s Properties Enhancement

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