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Brittle snap

Fused silica is slightly more brittle than borosilicate glasses and is therefore more easily fractured. Tubes up to just over 1 cm in diameter can be snapped with the fingers after scratching with a file or glass knife. Any ragged end so formed can be cleaned up with an abrasive wheel. [Pg.92]

Alloy with Memory. In seeking a way to reduce the brittleness of titanium, U.S. Navy researchers serendipitously discovered a nickel-titanium alloy having an amazing memory. Previously cooled clamps made of the alloy (nitinol) are flexible and can be placed easily in position. When warmed to a given temperature, the alloy hardware then exerts tremendous pressure. Use of conventional clamps for holding bundles of wires or cables in a ship or aircraft structure requires special tools. For this and other applications in industry and medicine, nitinol has been in demand. The alloy, however, is not easy to produce because only minor variations in composition can affect the snap back" temperature by several degrees of temperature. [Pg.1072]

After the repairs, the painters started the portable air compressor. The pressure in the sand pot increased. Without warning, employees in the area heard a loud bang. Three of the four stud bolts (which were hardened and made brittle by the heat of the welding operation) snapped apart. The sand pot charging lid harmlessly flew open. [Pg.180]

Texture. A hard biscuit has a crisp or brittle texture. This implies that it deforms in a fully elastic manner upon application of a force, until it breaks (snaps) at a relatively small deformation. Breakage goes along with a snapping sound. It appears from empirical observations that a crisp material has an apparent viscosity of at least 1013 or 1014 Pa s. The water content or temperature above which crispness is lost closely corresponds to Tg. Sensory evaluation shows that an increase in water content by 2 or 3 percentage units, or in temperature by 10 or 20 K, can be sufficient to change a crisp food into a soft (rubbery) material. [Pg.680]

In linear-elastic fracture, crack propagation (after Lcr has been reached) proceeds roughly at the speed of sound in the material (of order 1 km s-1). This gives rise to a snapping sound, typical for fracture of brittle materials. [Pg.716]

The capsule shell should be of the desired color, size, and brittleness. Traditional gelatin capsule shells should remain flexible. Under certain storage conditions, gelatin capsule shells can become hard and brittle. When the shells are squeezed between two fingers, a brittle shell will snap and in extreme cases shatter. Brittleness occurs due to cross-linking of the gelatin and this cross-linking adversely affects the dissolution of the capsule. Capsule color has also been known to fade over time. [Pg.204]

Anger gave him the strength to snap the last clip off the circulation fan unit he was working on the little plastic star shattered from the pressure, chips spinning off in all directions. Bombarded by heat from a possessed s fireball, then subjected to hard vacuum for a week, the plastic had turned dismayingly brittle. [Pg.318]

British thermal unit (Btu) A British thermal unit is the energy needed to raise the temperature of 1 lb of water ]°F (0.6°C) at sea level. As an example, one lb of solid waste usually contains 4,500 to 5,000 Btu. Plastic waste contains greater Btu than other materials of waste. See calorie energy consumption heat, brittle Easily broken, damaged, disrupted, cracked, snapped. See design-failure theory, Griffith metal fracture. [Pg.127]

Prepare the cantilever Etched silicon Ccintilever substrates are generally used for NC-AFM or TM-AFM, and silicon nitride cantilevers are used for C-AFM. In both cases, the cantilever probe should be inspected under the microscope when being used for first time. Use the sharp-pointed tweezers to remove the cantilever substrate from the container. Grasp the sides of the substrate, away from the lever and probe tip. Be very careful about avoiding any contact with the probe lever, since it will immediately snap off. Silicon is very brittle. [Pg.40]

Some substances are elastic (they deft>rm and then return to their original shape) and others plastic (they deform, and keep the new shape) or brittle (they readily snap). [Pg.107]

The brittleness of inorganic materials means that they readily break upon contact with macroscale objects. The polysiKcon legs used in the thermal actuator array above snapped when too much weight was appKed. Similarly, polysilicon microgrippers have been known to break if touched by a macro-object or if exposed to air velocities higher than 1 m/s [109]. [Pg.1580]

However, molecular adhesion is very different. This falls off in a very short distance of separation. As a consequence, these molecular adhesion forces cannot be measured with a meter ruler, but need a nanometer scale. The adhesion force may be high when the molecules are touching, but even a separation of one nanometer causes the force to drop almost to nothing. Thus the surfaces snap apart in a brittle fashion, totally different from the other types of adhesion force. The area under the curve is very small, hi other words, the energy of molecular adhesion may be negligible. Taking this energy for one square metre of joint, we define the work of adhesion ITin Joules per square metre. [Pg.38]

The blade of a ceramic knife will stay sharp for much longer than that of a steel knife, although it is more brittle and can be snapped by dropping it on a hard surface. [Pg.128]

Non-metallic elements have the opposite physical properties they are dull (not shiny), brittle (they snap under tension) and they cannot be drawn into wires (they are non-ductile) and cannot be hammered into thin sheets (they are non-malleable). Non-metals, with the exception of graphite, are non-conductors of electricity (insulators). [Pg.94]

Brittleness identifies material easily broken, damaged, disrupted, cracked, and/or snapped. Brittleness can result from different conditions such as from drying, plasticizer migration, etc. Brittle materials exhibit tensile S-S behaviors different from the usual S-S curves. Specimens of such materials fracture without appreciable material yielding. They lack toughness. Their brittle point is the highest temperature at which a plastic or elastomer fractures in a prescribed impact test procedure. [Pg.173]

To model the failure of pressure vessels, we must first differentiate between brittle fracture and ductile failure. The easiest way to do this is to think of the child s toy called Potty Putty or Silly Putty. If this material is pulled slowly, it will stretch to tens of times its original length before it breaks (ductile failure). However, if it is pulled sharply, it snaps with hardly any stretching (brittle fracture). In the right circumstances, metal components can also fail in either a plastic or brittle manner. [Pg.113]

The iron from the blast furnace usually contains a lot of carbon (up to 4 %) as well as other impurities. You saw that some of the iron is allowed to solidify, in moulds or casts. It is called cast iron. The carbon makes it very hard, but also brittle—it snaps imder strain. So these days is only used for things like gas cylinders, railings and storage tanks, that are not likely to get bent during use. [Pg.147]

The exact shape of the stress-strain curve will depend on the material, the rate of loading (how quickly and/or slowly the load is increased), and the temperature. The ultimate failure of the material can be abrupt (and often quite dramatic), where it simply snaps in half. This type of failure is called a brittle failure. The failure can also be slow and gradual, where the material begins to stretch and thin out, and eventually breaks. Or the failure can be a mixture of the two. The ratios of the elastic to plastic regions can also vary. But each material has a unique stress-strain curve, almost like a fingerprint. [Pg.60]


See other pages where Brittle snap is mentioned: [Pg.153]    [Pg.153]    [Pg.212]    [Pg.87]    [Pg.120]    [Pg.289]    [Pg.368]    [Pg.134]    [Pg.66]    [Pg.270]    [Pg.224]    [Pg.117]    [Pg.288]    [Pg.457]    [Pg.237]    [Pg.641]    [Pg.235]    [Pg.660]    [Pg.164]    [Pg.16]    [Pg.437]    [Pg.443]    [Pg.1111]   
See also in sourсe #XX -- [ Pg.148 ]




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