Papers by Keyword: Dies

Abstract: This paper presents a comparative analysis of 1200 V Silicon Carbide (SiC) MOSFETs characterized at bare die level and in TO-247 packaging. Static parameters including transconductance (g_m), drain leakage current (I_DS-OFF), output (I_DS-V_DS) and transfer characteristics (I_DS-V_GS), gate threshold voltage (V_GS(th)) and on-state resistance (R_DS(on)) are examined. Results show that the TO-247 package introduces parasitic resistance/inductance and higher thermal impedance, leading to disrupted g_m, though lower leakage I_DS-OFF, shifted V_GS(th), and elevated R_DS(on). The study quantifies the discrepancy between intrinsic die behavior and packaged device performance, underscoring the need to de-embed packaging effects for accurate device modelling and optimization.

Abstract: Wirecut Electrical Discharge Machining (WEDM) is a manufacturing process typically used to manufacture the machinery components in marine application with complex and challenging shapes and profiles. This study aims to investigate the effect of the EDM wire cut parameters on AISI 316 steel by analyzing the formation of Cr₂₃C₆. Cr₂₃C₆ can be formed in the grain boundary if the stainless steel is sensitized to a high temperature for too long. This compound becomes susceptible to intergranular corrosion than can reduce structural strength. The formation of Cr₂₃C₆ is of interest because this compound becomes vulnerable to intergranular corrosion than can reduce structural strength. The experimental variables in this study are pulse on time (i.e., 8 μs and 12 μs), servo voltage (i.e., 20 V and 30 V), and wire feed (i.e., 5 mm/min and 9 mm/min). The 0.2 mm brass wire is used during the EDM process. The result is then analyzed by surface roughness test, scanning electron microscope (SEM), and Energy-dispersive X-ray spectroscopy (EDS). As a result, the highest and lowest surface roughness values are 2.526 μm 1.771 μm, respectively. SEM results are seen in the pores of holes (craters) and fractures (microcracks). The result of EDS is the additions of elements Carbon (C) and copper (Cu), Oxygen (O). Increased carbon Chrom in HAZ sections allows for corrosion of grain limits.

Abstract: Price and time are two major concerns in the industry which encourages the development and manufacturing of new dies for sheet metal forming applications. Additive manufacturing (AM) and rapid tooling (RT) are now emerging techniques for producing cost-effective and fast production of sheet metal forming dies with excellent mechanical and wear resistance properties. The paper gives an insight into AM processes that were implemented in the tooling industry to enhance moulding efficiency and sheet metal forming processes. The advantages and challenges observed in using AM are highlighted and discussed as opposed to traditional tooling. The RT processes used in moulding and sheet metal formation are addressed, and their limitations are highlighted. The paper also discusses several possible application areas in which AM technologies can be used further to enhance the efficiency of the devices. Finally, discussion on current issues related to the use of AM in tooling has been presented.

Abstract: The article is devoted to tribological studies of a ceramic composite with a zirconia-based die in order to replace carbide wire drawing dies with ceramic. Sliding friction was done according to the scheme finger-disk without lubrication and with lubrication. The wear rate and friction coefficients were determined, on the basis of which it is proposed to produce portage dies-blanks from zirconium ceramics. The influence of sintering temperature on the mechanical properties of ceramics, especially cracking resistance, was studied. The optimum sintering temperature was determined by the criterion of fracture toughness. The formation of defects after the final firing was investigated. It was found that sintering at a temperature of 1600 ° C is more promising. An trial batch of zirconium ceramic dies showed positive results in the process of drawing copper wire in industrial situations.

Abstract: Abrasive wear and low cycle fatigue (LCF) have the greatest influence on the durability of dies. This paper presents a new criterion for estimation of the LCF of forging dies. The deformation model of Manson-Coffin is the classic model for the calculation of LCF. The pulsating cycle of loading dies and the phenomenon of cyclic thermal softening doesn’t provide implementation of the full Manson-Coffin’s model for the analysis of the tool life. At the same time the majority of researchers do not take into account the plastic strain component for estimation the fatigue durability of the dies and use only elastic component of the Manson-Coffin’s law or model of Basquin that is based on the analysis of the stress cycle. The present work uses the strain-kinetic criterion to analyze the durability of the dies that allows taking into account the elastic-plastic strain components and thermos-cyclic softening. During loading in bulk forging the first cycle is to be with plastic deformation while all remaining cycles would have to remain within the elastic limit due to metal hardening. Moreover it has been shown that cyclic softening effect may also be observed in the thermomechanical fatigue. This approach has been implemented for LCF simulation of the die in hot forging in FE program QForm by introducing a special subroutine. The comparison of results of the die fatigue failure simulation has shown good correspondence with practice.

Abstract: Among the Aluminum casting processes, High Pressure Die Casting (HPDC) is an efficient, versatile and economic way for producing large number of components. Nevertheless, because of the elevated amount of rejected castings, it is important to know which are the main causes of defect formation and their effects on microstructure and mechanical properties. This paper presents, within the European MUSIC project, an overview of the preliminary correlations obtained studying both castings with defect generator geometry, referred to as Horse-shoe Reference Castings, and industrial demonstrators, referred to as Gear Box Housing. The deduced correlations between static mechanical properties and casting defects highlighted interesting trends in both cases.

Abstract: Protective coatings are used today in many applications for reducing friction and wear of tools in hot-working process e.g. metal die casting, hot forging, metal die plastics injection. The main goal of undertaken investigation was to evaluate usability of those coatings for improving wear resistance of metal die applied in investment casting process for wax injection. The (Ti,Al)N and (Al,Cr)N PVD coatings were deposited onto X37CrMoV5-1 hot-work tool steel and their mechanical and tribological properties are characterized in the paper. Based on the results of microscope examinations, scratch test, hardness measurement the similar properties of (Ti,Al)N and (Al,Cr)N coatings were found. Moreover it was established that type of steel surface machining before coating deposition, i.e. grinding, electrical discharge machining (EDM) and milling, did not affect coating properties. Thin coatings replicate steel base roughness parameters as Ra, Rz and Rmax with over 95% of correlation. Based on tensile test results of wax/coated steel samples and wax/uncoated steel samples the lowest wax adhesion to (Ti,Al)N coating was confirmed.

Abstract: In industry of coins production, dies is proportionally compared with the production of coin. Dies, one of the essential components, is externally influenced by geometry, relief, setting parameter production and others. While, internally dies will be affected by its physical property and surface treatment. Phenomenon of dimension deformation and poor wear resistance on dies surface, are part of leakage factor in coin production. In this research, the mechanical properties of Isodur^TM steel is being controlled by heat treatment especially tempering treatment and TiN PVD coating with arc cathodic method, in order to produce coining dies. Isodur^TM steel samples are heated until temperature 1080^◦C in 30 minutes, then samples are quenched and has a single and double tempered treatment at temperature 550^◦C in each. After that, samples are coating with TiN and have variables of PVD process holding time 6 and 12 minutes. The result show that hardness of single temper treatment is 62.9 HRC on temperature 550^◦C is constant in Isodur^TM steel. While the double tempering treatment will decrease the hardness becoming 61.49 HRC and it will make the microstructure being finer than single tempering treatment. The variables of holding time PVD 6 and 12 minutes do not influence the roughness surface relief of coining dies, but they affect the wear resistance that is showed in average capacity production about 251,552 and 262,403 coin per dies by single tempered treatment, and average capacity production about 355,625 and 359,243 coin per dies by double tempered treatment.

Abstract: The poor quality of machining surfaces caused by the surface wear of the pressing dies and the corrosion of the pressing parts has been a major concern for manufacturing engineers. In order to decrease the surface wear of the pressing dies and the corrosion of the pressing parts, the drawing oil is always used during the pressing process. It is well known that the properties and the distributions of the drawing oil significantly influence lubrication, cool down, cleanness and stabilization for the pressing dies and parts. Therefore, it is very important for the operating limitation of the pressing process. This paper is base on the above statements to further investigate the effects of the high viscosity drawing oil on the tribological properties and the adhesions between the dies and parts. The results have not only an added advantage of technology of pressing process, but they are also very helpful in design the pair of the dies and parts in the future. Moreover, the purpose of better quality and faster product speed of the pressing process can then be obtained for the industry.

Abstract: In this study, new thin corrugated metal gasket will be developed by using simulation experiment. The optimal design and dies design for gasket manufacturing is determined by using computer simulation based on finite element analysis (FEA). In the design stage, the Taguchi method is used to predict optimal design of new thin corrugated metal gasket. The L9 orthogonal array was concerned to design experimental matrix for four factors with three levels. In the manufacturing stage, gasket product is simulated by using ANSYS 14.5 and experimental press forming process by using press hydraulic machine. From the result, the optimal design is the model with R = 3 mm, p = 6 mm, OH = 3 mm and h = 0.2 mm. Based on simulation results and experimental press forming product, it can be concluded that the virtual design from computer simulation results can be used for predicting the real product.