mechanical characterization of a new low carbon bainitic steel for high performance crankshaft

Abstract In the actual automotive environment, the need to increase the performances of materials is requiring extra engineering efforts. The possibility to develop new materials is very important. Indeed alternative solutions in terms of material choice allow designers to optimize their projects and keep low costs of production. Dealing with potential alternatives to traditional quenched and tempered steels for high stressed components, as just seen in previous work, bainitic grades could be a valid solution. This is particularly true if the mechanical performances are kept without compromise the economic savings of bainitic grades. So a detailed evaluation of the mechanical properties of these steels needs a further deepen also for applications requiring case hardening treatment. The scope of this article is to introduce and show the characterization phase of a new bainitic low carbon content for a high-performance crankshaft application. In details, a long-life fatigue resistance staircase test is performed after a gas nitriding treatment and the results are compared to the untreated material. The increment of the fatigue resistance is quantified and can be utilized by structural engineers to develop and optimized their projects. Moreover, the case hardened depth and microhardness profiles are collected and evaluated in terms of nitriding effectiveness (nitrogen diffusion)

a support structure design strategy for laser powder bed fused parts

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current challenges in material choice for high performance engine crankshaft

Abstract The segment of high-performance cars will progressively deal with the trade-off among cost saving, high performances and quality due to customers' higher expectations and the regulations requests for higher-power, safer, more intelligent and environmentally-friend cars. Dealing with these complicated systems requires additional designing phases and optimization of all components in terms of performances, reliability and costs. Among such mechanical parts assembled in an Internal Combustion Engine (ICE), the crankshaft is one that still requires extra attention regarding materials choice, thermal treatments, producing processes and costs. The aim of this work is to analyze the actual and future scenarios about the material choice for the crankshaft of high-performance engines. In particular, what is considered here is the actual development and improved quality reached by base materials and manufacturing technologies for this critical component of the engine. In this context, different materials are analyzed, together with surface hardening techniques, thermal treatments and their technical and cost saving potentials

Improvement of the Compilation Process of the Italian Income Certifications: An Application on the Tax Model of the Year 2016 (Part 2)

AbstractIn this second part, the essay focuses on a real case about the functional decomposition of the application, already dealt in Part 1. The real case described here is about the system design process for the 2016 tax return certification compilation. The input elements of this functional decomposition process are the compilation instructions, the project constraints and the clusters of non-conformity. The proposed method enables to select, on each analysis level, the robust decomposition among the possible substantial decompositions, such as the configuration with the minimum data content. The measure of the system's data content was determined using the technique of function point. The aim is to provide software designers with a robust logical design of the system, in order to respect the fiscal deadlines, satisfying the user's requirements and guarantee a solution of the problems in the operating environment. The proposed application has a strong pro-active value, as it leads to the development of ad hoc solutions, avoiding the implementation of unnecessary data entry that does not provide any benefit neither for the taxpayer, nor to the withholding agent. This approach also allows having the necessary technical documentation at hand, to plan and monitor the implementation of the time of action, thus facilitating the system adaptation in the years to come

THE LEAN SIX SIGMAAPPROACH FOR PROCESS IMPROVEMENT: A CASE STUDY IN A HIGH QUALITY TUSCANY WINERY

This paper describes the application of a Lean Six Sigma (LSS) project to a winemaking process in a high-quality, Italian winery. LSS is used to focus on the problem through a quantitative analysis of waste and quality performances. The LSS basic algorithm (called “DMAIC”) helps to detect and quantify critical aspects of the process for transferring liquid used in the cellar. The improvement solution is developed and applied through the modification of the cellar system and the process procedure. The results obtained with this solution are shown and discussed in this paper, so too the long term reliability of the improved process analyzed. The results obtained by this case study can help to understand the importance of the LSS method to drive the improvement of agricultural and agrofood productions also in terms of environmental impact which is strongly connected to waste reduction

Conceptual Design of a Decision Support System for the Economic Sustainability of Nonprofit Organizations

AbstractIn Italy, a continuous growth of nonprofit organizations has occurred in the last years. These organizations have been favoured by the concomitant reduction of direct public intervention (due to spending review) and the effect of the economic crisis on the business system. Despite their growth, nonprofit organizations present usually a critical lack in financial and economic management. In other words, their management does not consider all the factors related to economic balance, social success, reputation and promotion of their projects. The managerial role appears often to be overlooked compared to the actual needs and this results in a real limit for the growth and sustainability of these organizations. The present paper introduces a complete management review for the nonprofit using an Axiomatic Design based on the case study of one “Misericordia” (onlus) located in Florence. The proposed application leads to the definition of the minimum set of assessment tools that have to be considered and used as a Decision Support System (DSS) to support the management in a nonprofit organization. The DSS is developed as an integrated system of tools which allows a systemic approach tailored to meet the specificity of this kind of organization

Study on the Effect of Inter-Layer Cooling Time on Porosity and Melt Pool in Inconel 718 Components Processed by Laser Powder Bed Fusion

This paper investigates the effects on the material microstructure of varying the Inter-Layer Cooling Time (ILCT) during the printing process in laser powder bed fusion (L-PBF) multi-laser machines. Despite these machines allowing higher productivity rates compared to single laser machines, they are affected by lower ILCT values, which could be critical for material printability and microstructure. The ILCT values depend both on the process parameter sets and design choices for the parts and play an important role in the Design for Additive Manufacturing approach in L-PBF process. In order to identify the critical range of ILCT for this working condition, an experimental campaign is presented on the nickel-based superalloy Inconel 718, which is widely used for the printing of turbomachinery components. The effect of ILCT on the microstructure of the material is evaluated in terms of porosity and melt pool analysis on printed cylinder specimens, considering ILCT decreasing and increasing in the range of 22 to 2 s. The experimental campaign shows that an ILCT of less than 6 s introduces criticality in the material microstructure. In particular, at an ILCT value of 2 s, widespread keyhole porosity (close to 1‰) and critical and deeper melt pool (about 200 microns depth) are measured. This variation in melt pool shape indicates a change in the powder melting regime and, consequently, modifications of the printability window promoting the expansion of the keyhole region. In addition, specimens with geometry obstructing the heat flow have been studied using the critical ILCT value (2 s) to evaluate the effect of the surface-to-volume ratio. The results show an enhancement of the porosity value (about 3‰), while this effect is limited for the depth of the melt pool