No abstract

Equal‐channel angular‐extrusion (ECAE) may greatly alter polymer properties because it creates anisotropy in the microstructure. Tensile, fracture toughness, flexure, and ballistic impact tests were performed to quantify ECAE effects on polymethylmethacrylate (PMMA). Young's modulus increased by 5% for one process condition, while strength and elongation to failure remained the same or decreased. Fracture toughness improved by 178% under a one‐pass condition. Ballistic impact resistance changes after molecular orientation by ECAE; the failure mode is along the weak planes formed by the first process. The process that subjects the specimen to a second extrusion with 180° rotation produces more isotropic and ductile ballistic impact properties. POLYM. ENG. SCI. 45:314–324, 2005. © 2005 Society of Plastics Engineers.

No abstract

No abstract

Glass-fiber/polyacetal cylindrical rods prepared by conventional compounding and extrusion were processed by equal channel angular extrusion (ECAE). The initial material contained 109.8 mm long fibers with uniformly distributed fiber angle orientations between 11.8 and 56.0 . One extrusion pass with a soft matrix at 73 C directed the fibers to a loglogistic distribution with a mean orientation angle of 23.5 . ECAE at room temperature did this with mean fiber angles becoming 20.8 and 23.6 for one and two passes respectively. The interquartile range of the angles narrowed with reduced processing temperature and number of processing passes.