Journal of Advanced Materials in Engineering (Esteghlal)

---

The presence of defects in cold mercerizing of cotton goods led to the creation of a new method, called hot mercerizing in which caustic soda solution is used at a high temperature. Hot mercerizing is successfully used in cotton blended with some other fibers. In cotton/polyester blend fabrics, this treatment serves a dual purpose: subjectively, it imparts a silklike soft handle to the polyester and brings about mercerizing of the cotton. In this work, the mercerizing operation with caustic soda solution was performed on a 65/35 polyester/cotton fabric in sixteen different temperatures (from 15°C to 90°C), in two states: with tension and without tension. Finally, the effect of temperature of treatment on some properties of fabric such as tensile properties, weight loss, and shrinkage have been studied. Alkali treatment cause weight loss in cotton/polyester blend fabrics, the main part of the weight loss attributed to the polyester component of the blend. Increasing temperature leads to a corresponding increased in weight loss. The resulting weight loss leads to more yarn release and consequently, to the improvement of the drape and soft handle in the fabric. However, it decreases the tensile strength and causes weakness of the fabric, therefore, an optimum of temperature must be considered. In the alkali treatment, the internal stresses in the fabric can be released. Release of tension in the fabric causes shrinkage, particularly in the warp direction. The effect of tension on properties of cotton/polyester blend fabric is not considerable in alkali treatment.

---

In this paper, the effect of Equal Channel Angular Pressing (ECAP) process on the structure and mechanical properties of AM30 magnesium alloy was studied. The results showed a considerable effect of ECAP process on creating an ultrafine grain size structure. Scanning Electron Microscope indicated that the grain size dropped from 20.4 µm in the extruded form to 7.2 µm in the first pass and 3.9 µm in fourth pass. The fourth pass presented higher ductility and lower yield stress in comparison with the extruded case. This behavior can be explained based on higher rate of texture softening versus the effects of the grain refinement on strength. The hardness test on the samples cross-section showed an increase in hardness and a uniform strain distribution at higher ECAP passes.

---

In this study, the effect of mechanical alloying on the microstructure and phase constituents of Mg-6Al-1Zn-1Si system was investigated. To understand the thermal behavior, isothermal annealing was performed at three different temperatures of 350, 400 and 450 °C for 1h. The results showed the grain size initially decreases with increasing the milling time up to 35h and then slightly increases. In contrast, the lattice strain increases sharply with increasing the milling time up to 35h and then decreases. Second-phase intermetallic particle Mg2Si was produced during annealing and the amount of this phase was increased with increasing annealing temperature. The mechanical alloying process decreased the formation temperature of Mg2Si.