Ductile binders

Mattsson, S., and Nystrom, C. (2000), Evaluation of strength-enhancing factors of a ductile binder in direct compression of sodium bicarbonate and calcium carbonate powders, Eur. I Pharm. Sci., 10, 53-66. 

The success of hard metals in cutting tool applications is a result of their unique combination of hardness and toughness, tailored by controlling the ratio of binder to carbide phase, together with their unique microstructure. Both the ductile binder... 

The most widely used transition metal carbide is tungsten carbide, hexagonal WC, which is employed as the hard constituent in WC-Co hardmetals. Such hardmetals are sintered composite materials with 80-90% of hard particles such as WC embedded in a ductile binder phase such as Co. For these apphcations WC combines a number of... 

The fracture energy can be utilised as a parameter to describe the fracture resistance of asphalt concrete, and the fracture energy parameter is particularly useful in the evaluation of mixtures with ductile binders, such as polymer-modified bitumen. It has been shown to discriminate between these materials more broadly than the indirect tensile strength parameter determined by AASHTO T 322 (2011) (Wagoner et al. 2006). 

Compactibility is the ability of a material to form a compact with sufficient strength when a compression foree is applied. A ductile binder can withstand large deformations without breaking, whereas a brittle material fails having a negligible deformation. Both, ductility and brittleness favor bonding beeause new smfaces are produced and consequently, an increase in contact area between particles occurs at compression. 

Pyrophoric penetrators equal in effectiveness to those containing U are reportedly provided by those containing spark sintered bodies of 49—95% W, 4—50% Zr and a binder of ductile metal such as Ni, Fe, Co or Cu (Ref 115). Even though U is the most pyrophoric of all elements, it is not expected to see use as an incendiary because of its toxicity and its great value as a nuclear fuel... 

Asphalt—mbber is mixed and applied to roadways by several techniques. In one method, mbber and asphalt are mixed at ca 175—220°C for one to two hours. The hot mixture is applied to the roadway and covered with a layer of stone chips to form a chip seal. The mbber cmmb consists of scrap tires ground into particles less than 2 mm in diameter. Rubber-modified asphalt is also used for waterproofing membranes, crack-and-joint sealers, hot-mix binders, and roofing materials. The mbber improves asphalt ductility and increases its softening point. The aggregate adhesive bond is stronger, and the asphalt lasts longer. Production of rubber-modified asphalt has increased from 405 t in 1970 to 27,000 t in 1980 (41). Typically, about 2 t of mbber is used for 1 km of roadway. If it is assumed that asphalt—mbber contains ca 25% mbber and 75% asphalt, the potential demand for scrap mbber would be ca 40,500 t/yr, or ca 2% of the amount available. 

A major disadvantage of the materials using polymerized sulphur as the binder, is the time-dependence of their behaviour the polymerized sulphur is metastable and in all cases the ductility disappears within a relatively short period of time (a few months to about 15 months, Figures 2 and 3). This time-dependence was also found previously by Currell and his co-workers (19). Data on Sulphlex (17) show similar trends. 

Cemented carbides belong to a class of bard, wear-resistant, refractory materials in which the hard carbides of Group 4—6 (IVB—VIB) metals are bound together or cemented by a soft and ductile metal binder, usually cobalt or nickel. Although the term cemented carbide is widely used in the United States, these materials are better known internationally as hard metals (see also Refractories Refractory COATINGS Refractory FIBERS). 

Transition metal carbides and nitrides are not only inherently brittle at room temperature they are also difficult to manufacture. For engineering applications, the hard carbides (and nitrides) are therefore bonded or cemented by a ductile metal binder, usually cobalt or nickel (hence the name Cemented Carbides ). Additions of binder metal in the range of 5-20 wt% increase the toughness (transverse rupture strength) of the tools without seriously reducing hardness, rigidity, or compressive strength. Metallic binders also enable carbide products to be manufactured to full density. 

Unlike clay-based systems, modem ceramics require additives, termed binders, to provide the plasticity required for ductile-forming methods to be used. These organic additives serve to modify the rheological behavior of the ceramic suspensions and impart handling strength to the green, as-formed ceramic bodies. Their... 

Binder A material with a high bonding ability can be used as a binder to increase the mechanical strength of the tablet. A binder is usually a ductile material prone to undergo plastic (irreversible) deformation. Typically, binders are polymeric materials, often with disordered solid-state structures. Of special importance is the deformability of the peripheral parts (asperities and protrusions) of the binder particles [5],... 

Rheology of SA Binders. Conventional test methods such as softening point, viscosity, penetration, Fraas break point, ductilities, etc. have been used to characterize the rheology of SA binders (11). The physical structure of SA binders is complex, and the sulfur-asphalt and sulfur-aggregate interaction make correlations to asphalt and to binder properties for aggregate rather difficult. 

Cemented carbides represent a group of hard and wear-resistant refiactory composites in which hard carbide particles are bound together or are cemented by a ductile and tough binder matrix. Although the term cemented carbide is still widely used, mainly in English-speaking countries, and well describes the nature of the composite, they are even better known internationally as hardmetals. The latter term will be used in the following. 

CKD can be added to asphalt binder to produce a low ductile mastic asphalt Mastic asphalt is a mixture of asphalt binder and fine mineral material When mastic asphalt is produced using CKD mixed 50/50 with an asphalt cement binder, a potential exists for a relatively large volume replacement of asphalt cement... 

Sand molds and cores made with the binder compositions of the invention can be used to cast most metals, such as gray, ductile and malleable iron, steel, aluminum, copper-based alloys such as brass or bronze. Steel is usually cast at around 2900°F, iron at about 2650°F, brass and bronze at around 2100°F and aluminum at about 1300°F. 

Somewhat higher ductility is obtained by combining ceramic particles with a metallic binder phase. Such ceramic-metallic materials (cermets) are excellent under erosive and abrasive conditions. A well-known material is WC Co. Better corrosion resistance is obtained by alloying Co with Cr or by using alloys of Ni, Cr and possibly Mo as the binding phase. 

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