Effect of strain rate on the strength and ductility characteristics of polyamides

The main features are presented for dynamic tests in tension, compression, and shear with plastic strain rates up to 10⁵ sec^–1. An increase in strength characteristics and a reduction in ductility characteristics with an increase in strain rate are established with different forms of stressed state for the test materials. Experimental results confirm the necessity of studying the dynamic properties of polymer materials.Translated from Problemy Prochnosti, No. 9, pp. 19–22, September, 1991.     

Production of High-Quality Bars of Hypereutectic Silumins by Helical Rolling

A study is made of the possibility of improving the structure and properties of hard-to-deform hypereutectic silumins with the use of helical rolling (HRG) on the PVP 20-60 universal mill at the All-Union Scientific Research Institute of Light Alloys. The parameters of hot HRG are optimized by numerically modeling the deformation process in a three-high stand. The resulting data is confirmed experimentally by subjecting standard hypereutectic silumins 01390 and 01391 to HRG. The use of HRG makes it possible to refine the structure of hypereutectic silumins and improve their mechanical properties.