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[en] The development of new extraction processes to produce titanium in powder form leads Powder Metallurgy to an advantage position among the manufacturing processes for titanium. The cost reduction of base material, coupled with the economy of the powder metallurgy processes, give titanium industry the chance to diversify its products, which could lead to production volumes able to stabilise the price of the metal. This work reviews some of the Powder Metallurgy techniques for the manufacturing of titanium parts, and describes the two typical approaches for titanium manufacturing: Blending Elemental and Prealloyed Powders. Among others, conventional pressing and sintering are described, which are compared with cold and hot isostatic pressing techniques. Real and potential applications are described. (Author) 71 refs.
[en] This publication lists the 554 unrestricted reports and 200 papers published by the National Institute for Metallurgy during the first ten years of its existence. For ease of reference, these publications are also classified under the research programmes that gave rise to them
[af]Hierdie publikasie lys die 554 onbeperkte verslae en 200 referate wat die Nasionale Instituut vir Metallurgie gedurende die eerste tien jaar van sy bestaan uitgegee het. Hierdie publikasies word vir maklike verwysing ook onder die navorsingsprogramme wat tot hulle aanleiding gegee het, geklassifiseer
[en] At the first part of this paper review a description about cellular metal processes by liquid route, was made. In this second part, solid processes and metals deposition are described. In similar way, the different kind of processes in each case are reviewed; making a short description about the main parameters involved and the advantages and drawbacks in each of them. (Author) 147 refs
[en] The application of the iron based Powder Metal (PM) compacts in Ultra High Frequency Induction Welding (UHFIW) were reviewed. These PM compacts are used to produce cogs. This study investigates the methods of joining PM materials enforceability with UHFIW in the industry application. Maximum stress and maximum strain of welded PM compacts were determined by three point bending and strength tests. Microhardness and microstructure of induction welded compacts were determined. (Author)
[en] Aluminium alloy powder having a nominal composition of Al_93Fe_3Cr_2Ti_2 (at%) has been prepared using gas atomisation. The atomised powder present a microstructure of an aluminium matrix reinforced with a spherical quasicrystalline icosahedral phase, in the range of nano metre in size. The powder was consolidated into bars using warm extrusion. The microstructure of the extruded bars retains the quasicrystalline microstructure and the bars present outstanding mechanical properties, i.e. proof stress of 280 MPa at 300 degree centigrade. Upon heating the microstructure evolves towards the equilibrium. The thermal evolution was investigated by means of x-ray diffraction, differential scanning calorimeter, scanning electron microscopy and transmission electron microscopy. According to these observations a transformation in two steps is proposed. A first step consists in the decomposition of the supersaturated solid solution of the matrix and the quasicrystals, and a second step in the transformation of the quasicrystals into the equilibrium phases. (Author)
[en] The microalloying of tantalum with silicon has been effectively used on a commercial scale. However, data on effects of microalloying on processibility, microstructure and mechanical properties are not readily available. To develop some data, tantalum powder with various levels of silicon (0-50 ppm) was processed under identical conditions. Sheet samples were then annealed at different temperatures and evaluated via microstructural, chemical and mechanical tests. The recrystallization temperature was found to increase with silicon content, most probably as a result of the presence of an intermetallic (Ta3Si) phase. The mechanical properties of unrecrystallized tantalum are, as expected, significantly different from those of recrystallized tantalum
[en] This report presents a brief review of the DREV uranium research carried out on various aspects of the physical metallurgy of depleted uranium alloys. It includes (1) a survey of the early work on polynary alloys, (2) recent metallurgical investigations on various alloy systems and (3) miscellaneous studies on grain size refinement, grain growth, powder metallurgy, pyrophoricity and directional casting of uranium alloys. A general summary of most of the studies carried out during the last ten years is also presented
[en] Niobium and tantalum are added to titanium alloys to form new beta alloys with higher biocompatibility for biomedical applications. Both elements have a high melting point, that is the reason for their limited solid state diffusion. In this work samples of titanium with 3% at. niobium and tantalum have been manufactured by powder metallurgy. The effect of the compacting pressure, temperature and the sintering time on the strength, elasticity and ductility in bending has been studied. The results show that both elements behave similarly: flexural strength increases between 20-25%, elasticity between 0-10% and ductility over 150%. Therefore, the addition of these elements is beneficial to mechanical properties. Statistical analysis shows that the effect of temperature and pressure are important, while the effect of time is insignificant and even harmful in these alloys. (Author)
[en] A description is given of the activities of the Metallurgy Department at Risoe during 1974. The main fields of work are: General Materials Research, Materials Development, Fuel Elements and Fuel Modelling, and Materials Technology. Two articles, one on ''Danish Developments in Computer Modelling and Overpower Testing of UO2-Zr Fuel Pins'', the other on ''A New Model for the Plastic Deformation of Polycrystals'', are also included in the report. A survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff of the department during 1974 is included. (J.B.B.-S.)
[en] The aim of this study is to characterize the microstructure and mechanical properties of aluminum metal matrix composites (MMCs) containing 20 vol% of silicon carbide particles (SiC_p) with different particle sizes. The A359/SiC_p MMCs sinterted specimens were respectively manufactured from a blended powder and composite powders by a hot press technique. The consolidated composite with the blended powder exhibited a clustered region of reinforcement particles in the matrix, which was due to the influence of the interfacial debonding of the SiC_p/matrix during fracture. On the other hand, a homogeneous particle distribution of the composite powders and the SiC_p was observed in the sintered specimens after fracture. Homogeneous distribution of the MMCs and SiC_p was significantly affected by the method of the preparation or the powder materials. This phenomena was predominant elevation of the mechanical properties in these composites.