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The technology of pulse-plasma modification of the working surface of the die of 4Kh5MF1S tool steel (analogues are X40CrMoV5-1 in the EU and 4Cr5MoSiV1 in China) was considered. The mentioned tool is used for stamping billets of titanium VT6 alloy (wt.%: Al -- 3.0--6.8; V -- 3.5--5.0; Ti -- base), which is performed at temperatures of up to 700 °C. The die surface is heated, which leads to its oxidation and diffusion redistribution of alloying elements. Pulse-plasma stamping leads to the formation of elastic-plastic deformations of the surface layer in a tool steel, which in combination with pulsed thermal and electromagnetic effects provides a refinement of the alloy structure and intensifies the diffusion mechanisms of alloying elements. The studies showed that the modified layer (over 80 µm thickness) in 4Kh5MF1S steel, formed in the process of pulse-plasma treatment, contains up to 2.5 % carbon, up to 12 % oxygen and up to 3 % tungsten. In the mentioned layer the presence of nanocrystalline structures with a size of less than 100 nm was revealed. The hardness of the modified layer is more than 700 HV0.025. The surface roughness after pulse-plasma treatment did not change. Experience of industrial use of this technology showed that modification of a surface of the die from 4Kh5MF1S steel provided its high serviceability at a deep drawing of products from the heated (to 700 °C) sheet of VT-6 titanium of 3 mm thickness. [ABSTRACT FROM AUTHOR]

Annual production output of poly (ethylene terephthalate) (PET) fiber has been over 15 million tons in China due to its good mechanical properties and processability, but the shortage of hydrophilic group of PET has imposed many limitations to further extend its application. The PET fabrics were grafted with polyacrylic acid in inverse microemulsion after low pressure plasma treatment, and the microstructure and properties of the grafted fabrics were investigated with infrared spectroscopy, scanning electron microscope (SEM), hydrophilic and mechanical tests. The grafting yield was increased with the grafting time. The grafting polymer was in the granular form with its particle size ranging from a few micrometers to a dozen of micrometers, normally smaller than the fiber diameter. The moisture regain and water uptake increased while the air permeability of the grafted fabrics decreased with the increase of grafting yield. The bending rigidity and tensile properties show slightly complicated behaviors with grafting yield. The inverse emulsion grafting technique can be used to control the grafting polymer architecture. [ABSTRACT FROM AUTHOR]