Effects of Heating Rate and Strain Rate on Phase Transformation in Micro-Grinding

The phase transformation in the grinding process could have a significant impact on the processing performance of the products. Although grinding process can lead to high heating and strain rates, the current studies on the phase transformation typically consider temperature only that limits their accuracy. In this study, based on the phase transformation model, by conducting the micro-grinding experiment of maraging steel C250, the mechanism controlling impacts of heating and strain rates on phase transformation has been analyzed, and a new process optimization scheme to control phase transformation has been proposed. In this research was determinate main characteristic parameters of the phase transformation prediction model and influence of the heating rate parameters on the structure of the material. The main conclusions of this work are aimed increasing productivity, as well as criteria for optimizing the micro grinding process are defined

Effects of Heating Rate and Strain Rate on Phase Transformation in Micro-Grinding

The phase transformation in the grinding process could have a significant impact on the processing performance of the products. Although grinding process can lead to high heating and strain rates, the current studies on the phase transformation typically consider temperature only that limits their accuracy. In this study, based on the phase transformation model, by conducting the micro-grinding experiment of maraging steel C250, the mechanism controlling impacts of heating and strain rates on phase transformation has been analyzed, and a new process optimization scheme to control phase transformation has been proposed. In this research was determinate main characteristic parameters of the phase transformation prediction model and influence of the heating rate parameters on the structure of the material. The main conclusions of this work are aimed increasing productivity, as well as criteria for optimizing the micro grinding process are defined

Application of Bamboo Plants in Nine Aspects

Bamboo forests are undoubtedly one of the most abundant nontimber plants on Earth and cover a wide area of tropical and subtropical regions around the world. This amazing plant has unique rapid growth and can play an important role in protecting our planet from pollution and improving the soil. Bamboo can be used as a biofuel, food, and for architecture and construction applications and plays a large role in the local economy by creating job opportunities. The aim of this paper is to review the extraordinary tropical plant bamboo by explaining the mechanisms related to the growth and strength of bamboo and identifying ways to utilize bamboo in industry, employment, climate change mitigation, and soil erosion reduction

Genus <i>Decalepis</i>: Biology, Importance and Biotechnological Interventions

The steno-endemic species from the genus Decalepis are facing a high level of threat due to destructive wild harvesting. The genus claimed its paramount importance to mankind due to its unique tuberous root characteristics and exhibits a wide range of biological and medicinal properties, and is used in pharmaceutical and food industries. Plants of this genus are endemic to limited areas of peninsular India, such as the Eastern and Western Ghats, and according to the International Union for Conservation of Nature (IUCN), species from the genus Decalepis are considered globally critically endangered. The genus comprises of five species namely Decalepis hamiltonii Wight & Arn., Decalepis arayalpathra (J. Joseph & V. Chandras.) Venter, Decalepis salicifolia (Bedd. ex Hook. f.) Venter, Decalepis nervosa (Wight & Arn.) Venter, and D. khasiana (Kurz) Ionta ex Kambale. All the species of the genus Decalepis are being used by the tribal people and also in traditional Indian and Chinese medicine. International trade for this plant is also increasing, resulting in overharvesting. The traditional method of propagation, viz., seed germination and vegetative, are limited and jeopardizes the species population, whereas plant tissue culture provides the opportunity for extensive production of the plant in vitro without sacrificing their natural habitats. This review is aimed to systematize the up-to-date facts related to the Genus Decalepis with the exploration of their geographic distribution, chemical profile, pharmacology, biological activities, micropropagation, somatic embryogenesis, synthetic seed, and genetic transformation

The Investigation of TiO2 NPs Effect as a Wastewater Treatment to Mitigate Cd Negative Impact on Bamboo Growth

The recent emerging evidence reveals that titanium dioxide nanoparticles (TiO2 NPs) can be used as a wastewater treatment. This study provides new information about the possible detoxification role of TiO2 NPs as a wastewater treatment in plants under heavy metal stress, with an emphasis on the mechanisms involved. Here, we investigated the effects of TiO2 NPs as one wastewater treatment on a bamboo species (Arundinaria pygmaea L.) under in vitro Cadmium (Cd) toxicity conditions. A factorial experiment was conducted in a completely randomized design with four replications of four concentrations of Cd (50, 100, 200, and 300 µM) alone and in combination with 100 and 200 µM TiO2 NPs as two wastewater treatments, as well as a control treatment. The results indicated that TiO2 NPs concentrations enhanced enzymatic and non-enzymatic antioxidant activities and proline accumulation as well as reducing hydrogen peroxide (H2O2), superoxide radical (O2•−), and malondialdehyde (MDA) levels, which led to improved photosynthetic parameters with an eventual increase in plant biomass as compared to the control treatment. Therefore, TiO2 NPs improved the photosynthetic parameters of bamboo under Cd toxicity, which led to an increase in plant biomass. We concluded that the wastewater treatments of TiO2 NPs improved bamboo biomass through the scavenging of reactive oxygen species (ROS) compounds (H2O2 and O2•−), which was induced by the stimulation of the antioxidant capacity of the plant. TiO2 also protected cell membranes by reducing lipoperoxidation in bamboo under Cd toxicity. The concentration of 200 µM TiO2 NPs had the most impact in reducing Cd toxicity

Investigation of Temperature and Energy Partition During Maraging Steel Micro-grinding

AbstractThis study investigates the effect of process parameters on the temperature and energy partition during micro-grinding by finite element modeling (FEM) simulation and experimental validation. Finite element model was is used to predict the workpiece and chip temperature under different grinding conditions by refining the micro-grinding temperature field. Based on detailed analysis and physics-based modeling, the temperature on workpiece and chips are predicted. The finite element modeling and experimental validation have been presented herein for the micro-grinding energy partition into chips with chip temperature consideration. The results show that the temperature and energy partition investigation can help optimize the grinding process for minimized thermal damages. The results indicate that the pursuit of reducing energy partition into workpiece can be achieved not only by improving grinding speed, but also by increasing the workpiece speed and reducing the depth of cut appropriately

Effects of Milling Parameters on Distribution of Residual Stress During the Milling of Curved Thin-Walled Parts

With the increasing application of curved thin-walled parts, the evaluation and control of curved surface residual stress in milling are becoming increasingly demanding. However, effects of milling parameters on distribution of residual stress remains a major challenge in the present aerospace research areas. In this paper, , impacts of milling parameters on curved surface residual stress have been investigated in a series of residual stress experiments and simulations. It is found that the residual stress can be lowered by increasing milling speed and tool radius within a reasonable range. The superposition of curved surface residual stress under two machining conditions have been analyzed using the milling simulation model. It has been found that the curved surface residual stress induced by the subsequent cutting will be superimposed on the curved surface residual stress induced by the previous cutting and that the superposition rates of residual stress induced by up milling are larger than down milling

Investigation of Performance and Residual Stress Generation of AlSi10Mg Processed by Selective Laser Melting

During the selective laser melting (SLM) process, the scanned layers are subjected to rapid thermal cycles. By working on the mechanical properties, residual stress, and microstructure, the high-temperature gradients can have significant effect on the proper functioning and the structural integrity of built parts. This work presents a comprehensive study on the scanning path type and preheating temperature for AlSi10Mg alloy during SLM. According to the results, SLM AlSi10Mg parts fabricated in chessboard scanning strategy have higher mechanical properties or at least comparable to the parts fabricated in uniformity scanning strategy. In the SLM processing, the residual stress in different parts of the specimen varies with temperature gradient, and the residual stress at the edge of the specimen is obviously larger than that at the center. Under the chessboard scanning and preheating temperature 160°C, the residual stress in each direction of the specimens reaches the minimum. Under different forming processes, the morphology of the microstructure is obviously different. With the increase of preheating temperature, the molten pool in the side surface is obviously elongated and highly unevenly distributed. From the coupling relationship between the residual stress and microstructure, it can be found that the microstructure of top surface is affected by residual stresses σx and σy. But the side surface is mainly governed by residual stress σy; moreover, the greater the residual stress, the more obvious the grain tilt. In the XY and XZ surfaces, the scanning strategy has little influence on the tilt angle of the grain. But, the tilt angle and morphology of the microstructure are obviously affected by the preheating temperature. The results show that the residual stresses can effectively change the properties of the materials under the combined influence of scanning strategy and preheating temperature

Effects of Milling Parameters on Distribution of Residual Stress During the Milling of Curved Thin-Walled Parts

With the increasing application of curved thin-walled parts, the evaluation and control of curved surface residual stress in milling are becoming increasingly demanding. However, effects of milling parameters on distribution of residual stress remains a major challenge in the present aerospace research areas. In this paper, , impacts of milling parameters on curved surface residual stress have been investigated in a series of residual stress experiments and simulations. It is found that the residual stress can be lowered by increasing milling speed and tool radius within a reasonable range. The superposition of curved surface residual stress under two machining conditions have been analyzed using the milling simulation model. It has been found that the curved surface residual stress induced by the subsequent cutting will be superimposed on the curved surface residual stress induced by the previous cutting and that the superposition rates of residual stress induced by up milling are larger than down milling