31 research outputs found

    Goals and Contemporary Position of Powder Metallurgy in Products Manufacturing

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    This chapter is an introduction to the book on powder metallurgy (PM). It presents the basis of the selection of powder metallurgy technologies for manufacturing of products, including such applied in medicine and dentistry, and the state of the art concerning the general characteristic of powder metallurgy. The materials and products manufactured with the classical powder metallurgy methods are generally described. The last section presents the general contents of the book based on the above general information

    Powder Injection Moulding of Tool Materials and Materials Containing One-Dimensional Nanostructural Elements

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    As modern manufacturing methods have been developing, the application methods of powders have changed, and they do not always have to be moulded prior to sintering. The powder injection moulding (PIM) method is suitable for large-lot and mass production; still, powder consumption is not too high. The metal injection moulding (MIM) is an advanced technology and not as developed as classical pressing and sintering but constantly and dynamically developing. The technology is developing towards micro-MIM, that is, production of very small parts for miniaturised devices. The chapter presents the overview of powder injection moulding as specialist powder metallurgy method and its application for fabrication of tool materials. Specially, the fabrication of high-speed steels and carbide-steels on their matrix by powder injection moulding is descripted. In last part of the chapter, the results of own investigations of the structure with nanostructural elements of high-speed steels and carbide-steels on their matrix fabricated by powder injection moulding are presented

    Advanced Composites with Aluminum Alloys Matrix and Their Fabrication Processes

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    This chapter introduces advanced aluminum alloy matrix composites and their manufacturing processes. In the beginning, the state of the art is characterized and the general characteristics of aluminum and its practical applications are presented, starting with the history of aluminum. The current approximate distribution of bauxite resources in the world and the production of bauxite and alumina in the leading countries of the world, as well as the production of primary and secondary aluminum and the range of aluminum end products, are presented. Aluminum alloys intended for plastic deformation and castings, and composite materials in general and with a matrix of aluminum alloys in particular, have been characterized in general. Against this background, a detailed review of the results of the Author’s own research included in numerous projects and own publications on advanced composite materials, their production technology, their structure, and properties were done. The range of aluminum alloy matrices of composite materials was adequately characterized, which include AlSi12, AlSi7Mg0.3, AlMg1SiCu, AlMg3, AlMg5, and AlMg9, respectively. Composite materials tested in terms of manufacturing technology include three groups. The first group includes gas pressure infiltration with liquid aluminum alloys of suitably formed porous preforms. Porous frameworks as a reinforcement for pressure-infiltrated composite materials with a matrix of aluminum alloys are produced by three methods. Al2O3 powder with the addition of 30–50% carbon fibers is uniaxially pressed, sintered, and heated to thermally degrade the carbon fibers and create the required pore sizes. In the second case, the ceramic porous skeleton is produced with the use of halloysite nanotubes HNTs by mechanical milling, press consolidation, and sintering. A third method is SLS selective laser sintering using titanium powders. Another group of manufacturing technologies is the mechanical synthesis of the mixture of AlMg1SiCu aluminum alloy powder and respectively, halloysite nanotubes HNTs in a volume fraction from 5 to 15% or multi-wall carbon nanotubes MWCNTs in a volume fraction from 0.5 to 5%, and subsequent consolidation involving plastic deformation. The third group of analyzed materials concerns composite surface layers on substrates of aluminum alloys produced by laser feathering of WC/W2C or SiC carbides. The structure and properties of the mentioned composite materials with aluminum alloys matrices are described in detail. The chapter summary provides final remarks on the importance of advanced aluminum alloy composite materials in industrial development. The importance of particular groups of engineering materials in the history and the development of the methodology for the selection of engineering materials, including the current stage of Materials 4.0, was emphasized. The importance of material design in engineering design is emphasized. Concepts of the development of societies were presented: Society 5.0 and Industry 4.0. The own concept of a holistic model of the extended Industry 4.0 was presented, taking into account advanced engineering materials and technological processes. Particular attention was paid to the importance of advanced composite materials with an aluminum alloy matrix in the context of the current stage of Industry 4.0 of the industrial revolution. Growth in the production of aluminum, its alloys, and composites with its matrix was compared with that of steel. Despite the 30 times less production, aluminum is important due to its lower density. The challenges posed by the development in the Industry 4.0 stage, including the expectations of the automotive and aviation industry, force constant progress in the development of new materials with the participation of aluminum, including the composite materials with an aluminum alloy matrix presented in this chapter

    EFFECT OF THE HEAT AND SURFACE LASER TREATMENT ON THE CORROSION DEGRADATION OF THE Mg-Al ALLOYS

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    In this paper there is presented the corrosion behavior of the cast magnesium alloys as cast state, after heat and laser treatment. Pitting corrosion resistance of the analyzed alloys was carried out using the potentiodynamic electrochemical method (direct current), based on a anodic polarization curve. On the basis of the achieved anodic polarization curves, using the Tefel extrapolation method near to the corrosion potential, the quantitative data were determined, which describe the electrochemical corrosion process of the investigated alloys: value of the corrosion potential Ecorr (mV), polarization resistance RP (kohm.cm2), corrosion current density icorr (10-6A/cm2), corrosion rate Vcorr (mm/year) as well the mass loss Vc (g/m2<)

    Fabrication, Composition, Properties and Application of the AlMg1SiCu Aluminium Alloy Matrix Composite Materials Reinforced with Halloysite or Carbon Nanotubes

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    In this chapter, the characterisation of the halloysite nanotubes (HNTs) and multiwalled carbon nanotubes (MWCNTs) as the reinforcement in the composite materials was described. The original and author technology of production of the aluminium AlMg1SiCu matrix composite materials reinforced with halloysite or carbon nanotubes using powder metallurgy techniques, including mechanical alloying and hot extrusion and the range of own research in the case to determine microstructure, as well as mechanical properties of those materials was present. It was investigated that the addition of carbon and halloysite nanotubes causes a significant improvement in mechanical properties of the obtained nanocomposites. The investigation results show that the technology used in manufacturing nanocomposite materials can find the practical application in the production of new light metal matrix nanocomposites

    Effect of Milling Conditions on Microstructure and Properties of AA6061/halloysite Composites

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    AbstractIn this work, AA6061 matrix composites reinforced with halloysite nanotubes (HNT) were fabricated using respectively, mechanical alloying and uniaxial pressing and hot extrusion. Halloysite, being a clayey mineral of volcanic origin which is characterized by large specific surface, high porosity, high ion exchange and easy mechanical and chemical treatment can be used as alternative reinforcement of metal matrix composite materials. Halloysite nanotubes have recently become the subject of research attention as a new type of reinforcement for improving the mechanical, thermal and fire-retardant performance of polymers. Application of halloysite as the reinforcement in metal matrix composites is the original invention of the authors and it has been patented (PL Patent 216257). The powders morphology, particle size and apparent density of newly developed nanostructural composites were studied as a function of milling time, ball-to-powder ratio and milling speed. Obtained composite powders of aluminium alloy matrix reinforced with 10wt.% of halloysite nanotubes were characterized by SEM analysis. Microstructural observation reveals that mechanical alloying generate a uniform dispersion of nanoparticles in the AA6061 matrix. AA6061 reinforced with 10wt.% HNT composite powder has been fabricated at vial rotation speed of 400rpm within only 6h of ball milling. It has been proven that milling speed and ball-to-powder ratio has a significant effect on the time required to achieve a morphological change in the powder being mechanically alloyed. Moreover, it has been confirmed that the use of mechanical alloying leads to high degree of deformation, which – coupled with a decrease in grain size below 100nm and the dispersion of the reinforcing refined particles – causing increase of composite hardness. Manufacturing conditions allow to achieve an improvement of mechanical properties compared with the base material

    Microporous Titanium-Based Materials Coated by Biocompatible Thin Films

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    This chapter presents the outcomes of numerous own works concerning constructional solutions and fabrication technologies of a new generation of custom, original, hybrid, microporous high-strength engineering and biological materials with microporous rigid titanium and Ti6Al4V alloy skeletons manufactured by Selective Laser Sintering (SLS), whose pores are filled with living cells. The so constructed and fabricated implants, in the connection zone with bone stumps, contain a porous zone, with surface treatment inside pores, enabling the living tissues to grow into. As the adhesion and growth of living cells are dependent on the type and characteristic of the substrate it is necessary to create the most advantageous proliferation conditions of living cells inside the pores of a microporous skeleton made of titanium and Ti6Al4V alloy. In order to improve the proliferation conditions of cells ensured by a fully compatible substrate, internal coatings with TiO2, Al2O3 oxides and Ca10(PO4)6(OH)2 hydroxyapatite of the surface of pores of a microporous skeleton made of titanium and Ti6Al4V alloy with SLS was used. Two technologies have been chosen for the deposition of thin coatings onto the internal surfaces of pores: Atomic Layer Deposition (ALD) and the sol-gel of deep coating from the liquid phase

    Fabrication Technologies of the Sintered Materials Including Materials for Medical and Dental Application

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    This chapter of the book presents the basis of classical powder metallurgy technologies and discusses powder fabrication, preparation, preliminary moulding, sintering and finish treatment operations. A general description of the materials and products manufactured with the classical powder metallurgy methods is presented. New variants are characterised along with special and hybrid technologies finding their applications in powder metallurgy. Special attention was drawn to microporous titanium and to TiAl6V4 alloy fabricated using hybrid rapid manufacturing technologies with selective laser sintering/selective laser melting (SLS/SLM) used for innovative implant scaffolds in medicine and regenerative dentistry. Laser deposition, thermal spraying and detonation spraying of powders are also discussed as special methods in which powders of metals and other materials are used as raw materials

    Porous Selective Laser Melted Ti and Ti6Al4V Materials for Medical Applications

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    This chapter characterises scaffolds manufactured in line with the make-to-order concept according to individual needs of each patient. The clinical data acquired from a patient during computer tomography, nuclear magnetic resonance or using traditional plaster casts is converted by a computer into a virtual solid model of a patient’s loss. The model, through the multiplication of a unit cell, is converted into a porous model on the basis of which an actual object is manufactured with the method of selective laser melting (SLM) from Ti/Ti6Al4V powders. The created scaffold is characterised by good mechanical properties, which is confirmed by the results of the performed tensile and compressive strength tests. The material is additionally subjected to surface treatment consisting of the deposition of atomic layers of titanium dioxide with nanometric thickness
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