Extremely Light Weight Rheocast Components for Automotive Space Frame

2012 ◽  
Vol 192-193 ◽  
pp. 545-550 ◽  
Author(s):  
Mario Rosso ◽  
Ildiko Peter ◽  
Gianluigi Chiarmetta ◽  
Ivano Gattelli

This paper presents an analysis of a new rheocasting process suitable for the manufacturing of high performance automotive parts. The process is able for the realization of components using Al alloys. An important aspect is related to the possibility to obtain quite wide range of thicknesses, starting from 2.5 mm. The used alloy is the well known A356, with low Fe content, maximum 0.08 wt%. T6 heat treatments has been performed, while the soundness of the parts has been certified by non destructive tests. These parts are produced to be mounted on a top level and famous sport car. Non standard samples for mechanical tests have been machined directly from the components. Following the mechanical tests fracture surface analysis has been carried out by SEM to observe some morphological details and to evaluate the influence of the process and of the alloy conditions on the fracture behaviour. On the polished transverse sections of the samples morphological analysis has been performed. The obtained results shown high level of mechanical strength for all series of components. The reliability of the process is very high at a convenient level of manufacturing rate. The weldability of the parts has been demonstrated.

2016 ◽  
Vol 256 ◽  
pp. 319-327 ◽  
Author(s):  
Mario Rosso ◽  
Ildiko Peter ◽  
Ivano Gattelli

During the last decades under the enthusiastic and competent guidance of Mr Chiarmetta SSM processes attained in Italy at Stampal Spa (Torino) an unquestionable high level of industrial development with the production of large numbers of high performance automotive parts, like variety of suspension support, engine suspension mounts, steering knuckle, front suspension wheel, arm and rear axle. Among the most highlighted findings SSM processes demonstrated their capability to reduce the existing gap between casting and forging, moreover during such a processes there are the opportunity to better control the defect level.Purpose of this paper is to highlight the research work and the SSM industrial production attained and developed by Mr G.L. Chiarmetta, as well as to give an overview concerning some alternative methods for the production of enhanced performance light alloys components for critical industrial applications and to present an analysis of a new rheocasting process suitable for the manufacturing of high performance industrial components.


2014 ◽  
Vol 217-218 ◽  
pp. 471-480
Author(s):  
Ivano Gattelli ◽  
Gian Luigi Chiarmetta ◽  
Marcello Boschini ◽  
Renzo Moschini ◽  
Mario Rosso ◽  
...  

This paper concerns with the optimisation of the innovative rheocasting process to produce a new generation of brake callipers, characterised by very high reliability and strength. The attained very promising properties favoured their use on a very high performance car and the presented technique can be further extended for other important challenging applications. The prototype components are produced using T6 heat treated A357 alloy. Results on the samples machined directly from the produced callipers are in detail described and analysed. Pieces exhibiting some small defects, individuated by non-destructive tests, as well as defectless pieces have been underlined to severe industrial tests, e.g. high pressure tight, as well as severe bench tests, and it has been observed that the proposed technological process assure the fulfilment of the requirements contained in standards.


1976 ◽  
Vol 98 (2) ◽  
pp. 229-238 ◽  
Author(s):  
G. J. Walker

The influence of free stream disturbances on transition is discussed and it is noted that significant regions of laminar flow may exist on axial turbomachine blades despite the high level of disturbance to which they are subjected. A family of surface velocity distributions giving unseparated flow on the suction surface of an axial compressor blade is derived using data from detailed boundary layer measurements on the blading of a single-stage machine. The distributions are broadly similar to those adopted by Wortmann in designing high performance isolated aerofoil sections for operation at much higher Reynolds numbers. The theoretical performance of blades having the specified surface velocity distributions is computed for a wide range of conditions, and the effects of varying Reynolds number and other design parameters are analyzed. The results suggest the possibility of obtaining useful improvements in performance over that of conventional compressor blade sections. The computed performance values show an almost unique relation between the blade losses and the suction surface diffusion ratio. However the correlation of losses with the equivalent diffusion ratio is found to break down at high values of the latter parameter.


2006 ◽  
Vol 116-117 ◽  
pp. 505-508 ◽  
Author(s):  
Mario Rosso ◽  
Marco Actis Grande

This work aims at studying the possibility of optimising the heat treatment cycles of parts produced using the New Rheocasting process in order to reduce the total cost of the operation, attaining good mechanical properties for high performance parts. The mechanical properties and the microstructure features of the considered A 356 alloy and the relative produced parts have been analysed and studied on samples machined both from the as cast and from the heat treated compomnents. The obtained results showed the possibility of successfully modifying the T6 heat treatment cycle with economical benefits, maintaining at the same time comparable high level properties and performances, together with good dimensional precision.


2012 ◽  
Vol 504-506 ◽  
pp. 361-366
Author(s):  
Mario Rosso ◽  
Ildiko Peter

This paper presents an analysis of an advanced squeeze casting process suitable for the manufacturing of high performance industrial components more quickly and cheaply. After a short description of the process, some produced components are considered. The components, in A380 alloys, have been T6 heat treated and their soundness has been certified by non destructive tests. All considered components have been designed for advanced application in the automotive field, in particular for quite important sport cars. Standard samples for tensile and impact tests have been machined directly from the previous components. After the execution of the tests the fracture surface of samples has been observed by SEM in order to analyze details and to evaluate the influence of the process and of the alloy on the fracture behavior. On polished transverse sections of samples the microstructure of the alloy has been observed, highlighting a mainly globular shaped microstructure as expression of the attained semi-solid conditions during the processes. A critical analysis has been developed to evaluate the real potential and to present some criticism of the process.


2021 ◽  
Vol 27 (1) ◽  
pp. 60-64
Author(s):  
Álvaro Huerta Ojeda ◽  
Daniel Jerez-Mayorga ◽  
Sergio Galdames Maliqueo ◽  
Darío Martínez García ◽  
Ángela Rodríguez-Perea ◽  
...  

ABSTRACT Introduction The squat is an exercise that is widely used for the development of strength in sports. However, considering that not all sports gestures are vertical, it is important to investigate the effectiveness of propulsive force stimuli applied in different planes. Objective The main purpose of this study was to determine the influence of maximum isometric force (MIF) exerted on starting blocks over performance in 5, 10 and 20-meter sprints. Methods Seven high-level male sprinters (mean age ± SD = 28 ± 5.77 years) participated in this study. The variables were: a) MIF in squats and on starting blocks (measured using a functional electromechanical dynamometer [FEMD]), b) time in 5, 10 and 20-m sprints and c) jump height (measured by the squat jump test). For data analysis, a Pearson correlation was performed between the different variables. The criteria for interpreting the strength of the r coefficients were as follows: trivial (<0.1), small (0.1−0.3), moderate (0.3−0.5), high (0.5−0.7), very high (0.7−0.9), or practically perfect (>0.9). The level of significance was p < 0.05. Results There was very high correlation between MIF exerted on starting blocks and performance in the first meters of the sprint (5-m: r = -0.84, p = 0.01). However, there was small correlation between MIF in squats and performance in the first meters of the sprint (5-m: r = -0.22, p < 0.62). Conclusion The MIF applied on starting blocks correlates very high with time in the first meters of the sprint in high-level athletes. In addition, the use of the FEMD provides a wide range of possibilities for evaluation and development of strength with a controlled natural movement. Level of evidence IV; Prognostic Studies - Case series.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 438
Author(s):  
Yaqian Zhang ◽  
Maninder Meenu ◽  
Hansong Yu ◽  
Baojun Xu

China is a major producer of various kinds of food legumes. Some of the under-utilized food legumes are consumed by the local society from different areas in China. The antioxidant capacity and phytochemical profile of these under-utilized food legumes haven’t been investigated until now. In this study, colorimetric and high-performance liquid chromatography was employed to explore the antioxidant capacity and phytochemical profile of 21 under-utilized food legumes. Different legumes under investigation exhibit a wide range of variations in their total phenolic content (TPC), total flavonoids content (TFC) and condensed tannins content (CTC). Among all the legume samples, the velvet bean from Hechi, Guangxi exhibited the highest antioxidant capacity while the white flat bean from Shangrao, Shanxi presented the least antioxidant capacity. Gallic acid was observed to be a major phenolic acid and its content in the velvet bean was significantly higher compared to the other legume samples explored in this study. The composition of flavonoids was different among all the legumes. Kaempferol was observed to be the most predominant flavonoid. The findings of this study will be beneficial for plant breeders, food scientists and consumers for the better selection of germplasm with a high level of phytochemicals that in turn possess maximum health benefits.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1484
Author(s):  
Maximilian Pramreiter ◽  
Sabine C. Bodner ◽  
Jozef Keckes ◽  
Alexander Stadlmann ◽  
Cedou Kumpenza ◽  
...  

The currently pursued implementation of wood into novel high performance applications such as automotive parts require knowledge about the material behaviour including ultimate strength. Previous research has shown that fiber deviation seems to be the dominating factor influencing the strength of thin veneers. This study aims to further investigate and quantify the influence of fiber deviation in two dimension and different hierarchical levels on the tensile strength of thin birch veneers. The fiber deviation in- and out-of-plane as well as the micro fibril angle were assessed by means of wide-angle X-ray scattering. Tensile strength was determined in laboratory experiments. Results show a high variability for in-plane fiber deviation mainly constituted by knots and other growth influencing factors. Pearson correlations between strength and fiber deviation ranged from −0.594 up to −0.852. Best correlation (r = −0.852) was achieved for maximum in-plane fiber deviation directly followed by a combined angle of in- and out-of-plane fiber deviation (r = −0.846). Based on the results it was shown that fiber deviation in- and out-of-plane is the dominating factor influencing ultimate tensile strength of thin birch veneers. Further research in regard to non-destructive strength prediction is necessary.


2013 ◽  
Vol 21 (1-2) ◽  
pp. 1-16 ◽  
Author(s):  
Marek Blazewicz ◽  
Ian Hinder ◽  
David M. Koppelman ◽  
Steven R. Brandt ◽  
Milosz Ciznicki ◽  
...  

Starting from a high-level problem description in terms of partial differential equations using abstract tensor notation, theChemoraframework discretizes, optimizes, and generates complete high performance codes for a wide range of compute architectures. Chemora extends the capabilities of Cactus, facilitating the usage of large-scale CPU/GPU systems in an efficient manner for complex applications, without low-level code tuning. Chemora achieves parallelism through MPI and multi-threading, combining OpenMP and CUDA. Optimizations include high-level code transformations, efficient loop traversal strategies, dynamically selected data and instruction cache usage strategies, and JIT compilation of GPU code tailored to the problem characteristics. The discretization is based on higher-order finite differences on multi-block domains. Chemora's capabilities are demonstrated by simulations of black hole collisions. This problem provides an acid test of the framework, as the Einstein equations contain hundreds of variables and thousands of terms.


Author(s):  
Mebarek Belaoura ◽  
Dalila Chiheb ◽  
Mohamed Nadjib Oudjit ◽  
Abderrahim Bali

This study aims at a better understanding of the behaviour of very high performance concretes (VHPC) subjected to high temperatures. The temperature increase within the concrete originating from the hydratation exothermic reaction of cement is emphasized by the mass effect of the structures and can lead to thermal variations of around 50°C between the heart and the structures walls. These thermal considerations are not without consequence on durability and the physical and mechanical properties of very high performance concrete, such as the compressive strength. This work is an experimental research that shows the effects of temperature on the mechanical properties of very high performance concrete (VHPC) and compares them with those of conventional concrete and HPC. Test specimens in usual concrete, HPC and VHPC are made, preserved till maturity of the concrete, and then subjected to a heating-cooling cycle from room temperature to 500°C at heating rate 0.1°C/min. Mechanical tests on the hot concrete and cooling (air and water) were realized. The results show that the mechanical characteristics of VHPC (density, compressive strength, tensile strength and elastic modulus) decrease with increasing temperature, but their strength remains higher than that of conventional concrete.


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