1,721,055 research outputs found
Surface Modifications Induced by Roller Burnishing of Ti6Al4V Under Different Cooling/Lubrication Conditions
No full textThe paper presents a deep analysis of surface modifications induced by roller burnishing process of Ti6Al4V titanium alloy. The extensive experimental campaign has been performed based on a Design of Experiments at varying lubrication/cooling strategies (dry, cryogenic and MQL), roller radius, burnishing speed and burnishing depth. The resulting surface integrity has been analyzed in terms of surface roughness, micro hard-ness, microstructural changes and tribological performance. In particular, the wear rate of the burnished sample has been evaluated as a quality indicator of the process. The overall results show the influence of burnishing process parameters on surface quality and wear resistance of Ti6Al4V highlighting the capability of the process to significantly improve the above performance especially when cryogenic cooling is applied. Finally, the extensive experimental activity allowed to find a combination of processing parameters and lubrication conditions able to significantly improve the surface quality of the final component
Shape and dimensional accuracy in Single Point Incremental Forming: state of the art and future trends
No full textThe paper is aimed to discuss some relevant issues concerning an innovative sheet metal forming technology, namely Single Point Incremental
Forming. The advantages of this technology are addressed, including its capability to provide effective answers to some impellent industrial
requirements: process flexibility, strong customer orientation, production of highly differentiated goods at low industrial costs. As well some
relevant drawbacks are highlighted, mainly as concerns the level of accuracy permitted by the process.
A wide recognition of the research efforts in this field is presented, taking into account some general considerations on the difference sources of shape and dimensional errors, as well as the influence of the most relevant parameters. Finally, some strategies for error minimisation are presented and discussed
Recent advances in sheet metal single point incremental forming and friction stir welding
No full textWear Modeling in Mild Steel Orthogonal Cutting when using Uncoated Carbide Tools
No full textWear prediction in machining has been recently studied by FEM although the use of numerical methods for such applications is still a very challenging research issue. In fact, wear phenomenon involves many aspects related to process mechanics which require a very accurate modelling. In other words, only a very punctual code set-up can help the researchers in order to obtain consistent results in FE analysis. The high relative velocity between chip and tool requires effective material models as well as friction modelling at the interface. Moreover the prediction of temperature distribution is another critical task; in the paper some different procedures are discussed. Subsequently a wear model is presented and calibrated in order to obtain a suitable tool to be implemented in a FE code with the aim to describe the wear evolution during the simulation process. A proper designed experimental campaign supplied some reference data for model set-up and verify in the practical application. All these aspects are carefully discussed in the pape
A force measuring based strategy for failure prevention in incremental forming
No full textIncremental forming processes show a number of advantages compared to the traditional processes but, at the same time, some drawbacks are clearly known. Current problems, include the slowness of the process, low accuracy and a lack of knowledge in the field of material formability. This paper is focused on the latter issue: an industrially oriented methodology for detecting the approach of failure in incremental forming is proposed. The approach is based on the analysis of the trend of the forming force in order to assess whether the process can be run safely. If not, a proper strategy, to avoid material failure, is proposed and experimentally validated
On the effectiveness of numerical simulation in the prediction of profile distorsion in extrusion
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