The purpose of this study was to characterize the situation of Portuguese Small and Medium Enterprises (SMEs) concerning the certification of their Quality Management Systems (QMS), Environmental Management Systems (EMS) and Occupational Health and Safety Management Systems (OHSMS), in their individually form, to identify benefits, drawbacks and difficulties associated with the certification process and to characterize the level of integration that has been achieved. This research was based on a survey carried out by the research team; it was administered to 46 Portuguese SMEs. Our sample comprised 20 firms (43%) from the Trade/Services activity sector, 17 (37%) from the Industrial sector, 5 (11%) from the Electricity/Telecommunications sector and 4 (9%) from the Construction area. All SMEs surveyed were certified according to the ISO 9001 (100%), a quarter of firms were certified according to the ISO 14001 (26.1%) and a few certified by OHSAS 18001 (15.2%). We undertook a multivariate cluster analysis, which enabled grouping variables into homogeneous groups or one or more common characteristics of the SMEs participating in the study. Results show that the main benefits that Portuguese SMEs have gained from the referred certifications have been, among others, an improvement of both their internal organization and external image. We also present the main difficulties in achieving certification. Overall, 7 of the Portuguese SMEs examined indicated that the main benefits of the IMS implementation management included costs reduction, increased employee training and easier compliance of legislation. The respective drawbacks and difficulties are also presented. Finally, we presented the main integrated items in the certified Portuguese SMEs we examined.
a b s t r a c tA novel MMM (Multi-frequency, Multimode, Modulated) ultrasonic (US) technology was used to refine the as cast microstructure and improve the mechanical properties of a AlSi9Cu3 alloy. Ultrasonic vibration was isothermally applied to the melt for 120 s at different temperatures slightly above the liquidus temperature of the alloy, using different electric power values, before pouring into a metallic mould. The microstructure of the cast samples was characterized by optical and scanning electron microscopy and energy dispersive spectrometry. Ultrasonic vibration promoted the formation of small ˛-Al globular grains, changed the size and morphology of intermetallic compounds and distributed them uniformly throughout the castings. Ultimate tensile strength and strain were increased to 332 MPa and 2.9%, respectively, which are 50% and 480% higher than the values obtained for castings produced without vibration. The microstructure morphology and the alloy mechanical properties were found to depend on the electric power and the melt temperature, and by using a suitable combination of these parameters it is possible to achieve high refinement efficiency by treating the melts in the liquid state.
In this work, a Tie48Al alloy was induction melted and allowed to cool and solidify in a ZrO 2 based crucible with an inner layer of Y 2 O 3 , and the effect of superheating parameters (time and temperature) on the metalecrucible interface, alloy chemical composition, microstructure and microhardness is evaluated. Microhardness variation and segregation profiles of residual elements, namely yttrium and oxygen, from the surface to the inside of samples are presented and compared, in order to establish a relationship between the processing parameters, alloy contamination and the ''alpha-case'' extent. The alloy microstructure at the metalecrucible interface is characterized for each superheating time and temperature. The Y 2 O 3 crucible layer was found to suffer some erosion and be slightly dissolved by the molten alloy and the extent of that dissolution, and consequent metal contamination with yttrium and oxygen, depend on both superheating temperature and holding time. A relationship was found between oxygen concentration profiles and microhardness profiles of the a 2 þ g microconstituent, from the surface to the inside of samples, which depends on the superheating temperature, but is not affected by the holding time.
Although brasses are essentially copper and zinc alloys, they also contain other alloying elements such as lead, silicon, aluminium, iron, tin, manganese, nickel or arsenic whose presence and content are responsible for the wide variety of properties inherent to these materials.In this article, the effect of the chemical composition of brasses, considering each alloying element and the effective copper content, upon the machinability has been investigated.For that purpose, machinability tests have been carried out on a CNC lathe under lubricated conditions. The study includes both commercial alloys and samples prepared in laboratory. The experimental procedure consists on turning operations, during which cutting forces and surface roughness obtained in brass workpieces are measured. The chip class is accordingly evaluated.The statistic treatment of the results enables the establishment of correlations between the studied machinability parameters and the chemical composition of different kinds of brasses.
a b s t r a c tIn this work a Ti-48Al alloy was induction melted in a CaO crucible using different superheating temperatures. In the first stage, samples were allowed to cool to room temperature inside the crucibles, in order to simulate a low cooling rate, and in the second stage samples were centrifugally poured into a steel mould, in order to study the effect of the melting operation on the alloy contamination with oxygen. The effect of superheating temperature on the metal-crucible interaction, alloy chemical composition, microstructure and microhardness is evaluated. The CaO crucible was found to be slightly dissolved by the molten alloy and the extent of that dissolution depends on the superheating temperature. A relationship was found between oxygen concentration and microhardness profiles of the a 2 þ g microconstituent, from the surface to the inside of samples, which depends on the superheating temperature and cooling rate.
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