Powder metallurgy methods

Morris, D. G. Munoz-Morris, M. A. Relationships between mechanical properties, grain size, and grain boundary parameters in nanomaterials prepared by severe plastic deformation, by electrodeposition and by powder metallurgy methods. J. Metastable Nanocrystal. Mater. 15-16, 585-590 (2003). 

A major challenge is the densification of the graded powder compacts. The processing of FGM materials by powder metallurgy methods often faced undesirable excessive bending or warping of the component after sintering (Miyamoto et al., 1999). Due to excessive thermal residual stresses, cracks and other defects may often be observed in the final FGM component unless properly manufactured. 

Pis are essentially nonfiisible and difficult to fabricate by conventional shaping processes. Parts are fabricated by techniques ranging from powder metallurgy methods to modifications of conventional injection, transfer, compression, and extrusion that include ram instead of screw plastication (Chapter 5). 

Rigid permanent magnets have a smaller maiket than flexible magnets. These magnets are formed by injection molding or powder metallurgy methods. Major applications are in fractional-horsepower motors, TV components, toys, and latches. The binder for these molding compounds is often nylon. 

Fullerene crystals can be produced at high yield. By counter diffusion from fullerene solution to pure isopropyl alcohol solvent, fullerene single crystal fibers with needle shape were formed. Needle diameters were found to be 2-100 pm and their lengths were 0.15 = 5 mm. Buckyball-based sintered carbon materials can be transformed into polycrystalline diamonds at less severe conditions using powder metallurgy methods. 

In order to prepare sinters based on HAp, powder metallurgy method was employed in this study, which allowed to obtain porous materials with beneficial biofimctional properties. 

For the purposes of this work and creation of ceramic composites (HA+Z1O2)/ powder metallurgy method was employed, which allowed to receive porous materials based on... 

Drawbacks of these processes are capital cost and limited flexibility. Use of plasma spray deposition techniques requires sufficiently smooth surface of the underlying layer to be coated. Preformed perforated alloy sheets are thus preferably used for these processes. If the alloy is to be processed by powder metallurgy methods, fine-grained alloy powder is more favorable to produce substrate with small pore size and surface roughness. On the other hand, the resulting enhanced specific surface area may yield, after a certain operating time to Cr depletion in the porous substrate. This might induce non-protective breakaway oxidation if the critical Cr threshold is reached and subsequent breakdown in electrochemical performance. 

A eomposite TiB2-Fe powder obtained by a SHS teehnique may be reeommended for the produetion of maehine parts for eonstruetion and instrumental purposes by powder metallurgy methods, as well as for the deposition of proteetive eoatings [2004Lep]. 

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