The different sizes of waste tyre rubber particles and precipitated silica-filled natural rubber composites were investigated to evaluate the vibration damping behavior of the waste tyre rubber filled rubber composites. In this work, waste tyre rubber particles prepared in three different sizes (100–250, 550–700, and 1000–1150 µm) using ambient grinding process. Then the particles blended with natural rubber and silica compounds, and the blend was synthesized by two roll mill and hydraulic press vulcanization. The various proportions of prepared samples in all sizes were characterized in respect of their vibration damping behavior. The results indicated that large size of waste tyre rubber-filled natural rubber composites showed excellent vibration damping performance compared with other sizes used and were evaluated by both direct and indirect methods. Differential scanning calorimeter study showed that, use of large waste tyre rubber provided more energy absorption than other sizes used which led to increase the damping characterization. Owing to excellent damping performance, large waste tyre rubber-filled natural rubber composites accurately used in the applications where vibration damping is considered as important design criterion.

In the present work, a comparative study of the shape memory and thermo-mechanical behaviour of four alloys containing different amount of samarium have been carried out at a strain rate of 0.08 × 10-6s-1. After hot rolling, annealing and solution treatment, the alloy samples were tensile deformed at room temperature from 1% to 5% and were then recovered at 600 °C for 20 minutes repeatedly for six times to complete six training cycles. It is found that thermo-mechanical treatment (training) results in improvement of shape memory effect and has a significant influence on mechanical parameters like proof stress (σ: 0.002), critical stress (σ: 0.0008) and strain hardening exponent. The improvement in shape memory effect by thermo-mechanical treatment can be regarded as the effect of reduction in the values of proof stress and critical stress during training which facilitates the formation of ε (martensite). It has also been noticed that excessive training may result in the formation of ά (martensite) due to continuous softening of the alloy during training, thus degrading the shape memory effect. Finally, it has also been noticed that the addition of samarium increases the values of proof stress, critical stress and strain hardening exponent. Although the addition of samarium increases the values of proof stress, critical stress and strain hardening exponent yet it has not an adverse effect on shape memory effect. In this paper, the effect of thermo-mechanical treatment on mechanical parameters such as proof stress, critical stress, strain hardening exponent and their influence on shape memory effect is discussed.