Study the Effect of Absorption Solution for Same Composite Polymeric Material
In this paper concerns an investigation of absorption solution in materials of polymeric composite were prepared two types of the matrix material were used (PE,PVC). Also two types of fiber were used (woven and short glass fiber ).with volume fraction 20%. The sample were immersed in different solution (NaCO3-KOH –HCL , Normality 0.5 N) for equal time at constant temperature (room temperature ±20C ) . The result show that the relative mass gain increased with increasing the immersion time till they tend saturation moisture mass after that the relative mass gain decreased . The result show that sample in (KOH)solution had higher mass gain while the sample immersed in (HCL) had lower mass gain .Also the results show that the sample immersed in (NaCO3) has maximum diffusion coefficient which means minimum absorption resistance, while the sample immersed in (HCL) has minimum diffusion coefficient which means maximum absorption resistance.
THE STUDY OF SOLUTION ABSORPTION AND DIFFUSION COEFFICIENT IN EPOXY COMPOSITE REINFORCED WITH GLASS FIBERS
Diffusivity behavior and diffusion coefficient was investigated in this paper for epoxy composite reinforced with glass fibers (woven roven and random direction) together as a sandwich with volume fraction (44). The samples were immersed in different solution for equal time at constant temperature (room temperature ±18 o C). The result show that the relative mass gain increased with increasing the immersion time till they tend saturation moisture mass (M∞) after that the relative mass gain decreased. The result show that the samples immersed in (kerosene) solution had higher mass gain while the samples immersed in distill water had lower mass gain and the samples immersed in other solution (Benzene, HNO3, KOH, H2O as received) had relatively mass gain between them. Also the results show that the samples immersed in benzene has maximum diffusion coefficient (30.219mm 2 /day) which means minimum absorption resistance while the samples immersed in (H2O as received) has minimum diffusion coefficient (0.191mm 2 /day) (maximum absorption resistance).
Evolution of carbide precipitates in Hastelloy N joints during welding and post weld heat treatment
Abstract The effects of welding and post weld heat treatment (PWHT) on the morphology, composition and lattice parameter of the precipitates in the welding joints of Hastelloy N alloy have been investigated. Joint samples were prepared using a gas tungsten arc welding process with ERNiMo-2 fillers, and then solid-solution treated at 1100 °C for 20 min. After welding, eutectic M6C carbides can be observed in the heat affected zones (HAZ) and weld zones (WZ). These eutectic M6C carbides become spheroidized during the following PWHT. The concentration of Si decreases during the transformation from the primary ones to eutectic ones, and then increases during the spheroidizing process. The total concentration of Si + Cr in M6C carbides remains stable during welding and PWHT. At the same time, the heat leads to the outward diffusion of Mo from the M6C carbides, which results in a decrease of the lattice parameter.