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Laser-assisted machining (LAM) has emerged as an effective process to facilitate the machining of several difficult-to-cut materials, including ceramics, titanium alloys, and nickel alloys. During LAM, the material is preheated by a laser beam, which leads to thermal softening. The softened material is removed by the cutting tool. Methods of improving LAM, by reducing cutting force, increasing tool life, and improving surface roughness, have been studied. While LAM effectiveness has been proven, there are few studies about LAM efficiency. In this study, the energy consumption of LAM laser power and depth of cut was analyzed for Ti-6Al-4V alloy. In addition, LAM process efficiency compared with conventional machining (CM) was experimentally analyzed, and optimized conditions were obtained. Under optimal conditions, LAM machining efficiency and process efficiency were improved by 230% and 104%, respectively, compared with CM.

Laser assisted machining (LAM) has emerged as one of the technologies that can be effectively employed to machine difficult-to-cut materials such as nickel alloy, ceramics and titanium that are increasingly used in the medical instruments, automobiles and aerospace industries. LAM has been widely studied, however most of those studies were basic research on turning or milling with a simple tool path. To machine complex shaped products in three dimensions further research on laser-assisted milling (LAMill) is required. In this study, laser assisted acute angle milling was proposed as a stepping stone for machining complex shapes. When acute angle machining was performed with LAMill, two factors affecting machining characteristics were identified. These factors were the preheating distance ( d P ) and distance between the laser beam focus and center of the cutting tool ( d L ). Prior to experimental verification, the proper depth of cut (DOC) and d P were determined by transient thermal analysis using the software ANSYS. Experiments were carried out using the same machining conditions for material removal rate (MRR) in order to confirm the effect of d P and d L on the machining characteristics. Experimental results showed that d P affects cutting force and d L affects tool wear. The range of d P and minimum d L needed to improving machinability during laser assisted acute angle milling were experimentally verified. Based on these results, the minimum acute angle that can be machined using LAMill was also derived.

The automotive industry is investing great effort to reduce the weight of vehicles to improve fuel efficiency and performance. To develop a lighter vehicle, Ultra high strength steel (UHSS) is being increasingly used, and is the focus of efforts to develop innovative sheet steel with high strength, durability and formability, including projects such as Ultra-light steel auto body (ULSAB) and Ultra-Light steel auto closure (ULSAC). Because UHSS is very difficult to form at room temperature, roll forming and hot forming processes have been proposed. However, the productivity of these processes is significantly lower than cold forming. In this study, a seven step cold forming process is proposed for forming a lower seat rail using 1180 TRIP steel, and was found to be more conducive to productivity than other processes. The design of the proposed forming process was determined by forming analysis and experiment. The forming analysis was carried out using DEFORM software, and the experiments were carried out using a mechanical press machine. The weight of conventionally formed seat rails (DP 980) and the proposed seat rails (1180 TRIP steel) were compared to determine the weight reduction.

Laser-assisted machining (LAM) is being actively studied as a new method for machining difficult-to-cut materials. In LAM, machining is performed after preheating the material using a laser. Among difficult-to-cut materials, silicon nitride, a type of ceramic material, is difficult to machine due to its high strength at high temperature and high thermal conductivity. Although machining of silicon nitride using laser-assisted turning has been performed, there are few studies and results using laser-assisted milling because it is difficult to maintain the proper preheating temperature of silicon nitride. So, in this study, three preheating methods, one-way, zig-zag, and back-and-forth, are proposed for machining silicon nitride using laser-assisted milling. The preheating effect according to the three preheating methods is analyzed by finite element analyses and experiments. And, the back-and-forth method is verified to be the most effective method.

Today, hybrid processes have a great influence on various material process fields due to factors such as improvements in the machinability and reductions of process forces. Also, the development of hybrid processes represents a new opportunity for the growth of manufacturing technology. Hybrid processes are developed to enhance the advantages of individual processes. The effect of hybrid processes is better than the sum of the advantages of a single process. Many researchers have studied a number of approaches to combine various manufacturing processes. Specifically, since the development of the laser, it has been applied in various engineering fields. Moreover, interest in laser and non-laser hybrid processes is recently increasing in various industries. The laser is a type of non-contact thermal energy technology and is used in material processing. The laser heat source can be used for the heating and preheating of various materials. In this paper, the laser is selected as an energy source and laser-assisted hybrid processes over the past five years are reviewed, including those related to machining, welding and coating processes. The last part of this paper discusses the trends in future research on laser-assisted hybrid processes.

Astrocytes are the most abundant cells in the brain, playing vital roles in neuronal survival, growth, and function. Understanding the mechanism(s) regulating astrocyte proliferation will have important implications in brain development, response to injury, and tumorigenesis. Cyclin B1 is well known to be a critical regulator of mitotic entry via its interaction with cyclin-dependent kinase 1. In rat astrocytes, we now show that the mRNA binding protein cytoplasmic polyadenylation element binding protein 1 (CPEB1) is associated with cyclin B1 mRNA and that this interaction is enriched at the centrosome. In addition, if growth-arrested astrocytes are stimulated to divide, CPEB1 is phosphorylated and cyclin B1 mRNA is polyadenylated, both hallmarks of CPEB1 activation, resulting in an increase in cyclin B1 protein. CPEB1 binding to mRNA initially inhibits translation; therefore, removing CPEB1 from mRNA should result in an increase in translation due to derepression. Indeed, when we either knocked down CPEB1 protein with siRNA or sequestered it from endogenous mRNA by expressing RNA containing multiple CPEB1 binding sites, cyclin B1 protein was increased and cell proliferation was stimulated. Our data suggest a mechanism wherein CPEB1 is bound and represses cyclin B1 mRNA translation until a signal to proliferate phosphorylates CPEB1, resulting in an increase in cyclin B1 protein and progression into mitosis. Our results demonstrate for the first time a role for CPEB1 in regulating cell proliferation in the brain.