In this study, as for the re-casting, surface alloying and re-solidification layer of this alloys at the work piece level machining with Wire Electro discharge machining (WEDM), changes of surface micro hardness with changes of operational parameters has been studied. Therefore, study shows using surface alloying phenomena with the diffusion of wire material into the machined surface and selection of operational parameters and suitable materials for wire cutting, surface mechanical properties can be modified simultaneously with the workpiece machining process. Also Shown in this study, by changing operating parameters such as peak power and open circuit voltage, the diffusion of wire material into the workpiece surface layer is increased, whereas with increasing pulse off time and dielectric flushing pressure, the diffusion of wire material into the workpiece surface layer is decreased. At last with increasing these parameters also change of micro hardness surface layer accompanied by a change alloy surface layer formed on the surface. Manuscript profile

The main target of this paper is to obtain an optimum wedge angle for best static and dynamic performance of a V-shaped clamp band separation mechanism. For this purpose, by using the finite element method, the proper 3D model for V-clamp band mechanism has been modelled and analysed in Abaqus/Explicit solver. In order to study the effect of wedge angle on bending and axial stiffness of V-clamp joint, many quasi-static analyses with different wedge angles were accomplished so the relation between wedge angle and axial stiffness of V-clamp joint under symmetric bending loading is extracted. In the next step, dynamic analyses were accomplished so the relation between wedge angle and separation time (duration between trigging moment and the time of disconnecting between flanges and wedged clamps) is extracted. For verification, this project results have been compared with the results of other researches and good agreement is observed. The results show that the optimal wedge angle for obtaining maximum stiffness together with minimum spring back disconnection time for the V-clamp band mechanism is 20˚. Manuscript profile

In this study, the compressive stresses of dodecahedron diamond lattice structures have been investigated. The finite element method has been used for Stress analysis. After the simulation, it was found that more stresses are applied at the junction of the struts of this structure due to the application of compressive force. For this purpose, the connection point of the structure’s struts was strengthened by spherical connections, and a new type of dodecahedron structure was created. The validation and effect of spherical connections in compressive stresses have been evaluated experimentally. Two types of diamond lattice structures are made of stainless steel 316L by the SLM method. The results show that in the same condition, the use of spherical connections with twice the diameter of the structure’s struts helps to strengthen the structure and increase its compressive strength by 18% compared to the simple structure. Manuscript profile

نانو ذرات مورد استفاده در مواد مرکب زمینه فلزی دارای انواع مختلف و خواص فیزیکی، شیمیایی و مکانیکی متفاوتی می باشند که باعث بهبود سختی، مقاومت مکانیکی، سایش و خواص دمایی می شوند و قابلیت های ماشینکاری مواد را تغییر می دهند. در این تحقیق به بررسی پارامترهای ماشینکاری تخلیه الکتریکی ماده مرکب الومینیوم تقویت شده با نانوذرات اکسید تیتانیوم پرداخته می شود. هدف از این تحقیق بررسی تاثیر شدت جریان، ولتاژ، زمان روشنی و خاموشی پالس و نانو ذرات اکسید تیتانیوم بر نرخ براده برداری، سایش ابزار و زبری سطح می باشد. از نفت سفید به عنوان دی الکتریک و الکترود مسی به عنوان ابزار و تجزیه و تحلیل واریانس برای اعتبار سنجی آزمایشگاهی استفاده می شود. نتایج نشان داد نانو ذرات سرامیکی اکسید تیتانیوم با توجه به ایتکه غیر هادی هستند تاثیر زیادی بر پارامترهای ماشینکاری ندارند و حین فرایند ماشینکاری تخلیه الکتریکی ذوب نمی شوند و شدت جریان و زمان روشنی بیشترین تاثیر بر نرخ براده برداری، سایش ابزار و زبری سطح دارند. با افزایش شدت جریان و زمان روشنی پالس سایش ابزار و زبری سطح زیاد شده و با افزایش زمان خاموشی پالس سایش ابزار کم می شود. به طور متوسط نرخ سایش الکترود ابزار در آلومینیوم 2024 تقویت شده با نانو ذرات اکسید تیتانیوم 5 درصد به میزان 46/3 درصد معادل 346/0گرم بیشتر از نمونه آلومینیوم 2024 از نظر وزنی است. Manuscript profile