Heat quenching

Mix iron and hematite powder, pelletize the mixture and heat to 837 °C in a sealed silica or gold tube for 24 h. After heating, quench in liquid N2 (Battle and Cheetham, 1979). 

In general, as pointed out By Cook (Ref 9, p 272), the precariousness (ie, hazard sensitivity) of Slurries is low, primarily because of the heat quenching effect of the Slurries water content. Thus Slurries are resistant to subsonic impacts... 

At least two different glass transition temperatures have been reported for PVdF homopolymer. Owing to the large proportion of crystalline structure in this polymer and the rapid crystallization which occurs while heating quenched amorphous samples, it is difficult experimentally to obtain an unambiguous, well-defined second-order transition. Mandel-kem, Martin, and Quinn (16) reported a value below — 40°C based upon an extrapolation of the Tg data for vinylidene fluoride-chlorotri-fluoroethylene copolymers in accordance with the Fox equation (6),... 

The NC/PCL data present a different situation. Blends of 25 and 40% NC showed the opaqueness and a DSC endotherm, which indicate the presence of crystallinity. Consequently, melting and quenching produced lower Tgs as expected. Pure NC and 50% NC did not show either of these features. Yet, the Tg dropped from 338 to 328 K for NC and from 283 to 271 K for 50% NC after the heating-quenching cycle. Blends of 65 and 75% NC showed high initial Tgs but failed to show any transition after quenching. 

Poly(ethylene terephthalate) when quenched from the melt has 0% crystallinity when it is heated through the modulus drops dramatically as indicated. Specimens of crystallinity 26%, 33%, and 40% have modulus-temperature plots as shown. These three values of crystallinity were produced by heating quenched specimens at the temperatures prior to the temperature scan (after lllers and Breuer). 

This assumption leads to constant transformation temperatures. Any shifts of the phase transformations due to varying heating/quenching rates T are exduded. For the consideration of materials data depending on T and T transformation models must be applied, (Avrami, 1939 1940 Koistinen Marburger, 1959 Leblond Devaux, 1984). Such models take the temperature history into account and allow for the calculation of e.g. different phase volume fractions and the resulting materials data, (Kang Im, 2007). 

N. Tatsumi and T. Fukuzaki, Development of Long-Length Rapid-Heating Quenching and Transformation (RHQT) Processed NbsAl Conductors , Nippon Kinzoku Gakkaishi, 2004,68,616... 

When DU is alloyed with Mo or Ti (commonly a U-0.75%Ti alloy) and post-treated through heating/quenching regimes, the material is as strcaig as quench-hardened steel with a tensile strength of ca. 1,200 MPa and yield strength of 700 MPa. The combination of extreme hardness and density (19,050 kg m -1.6 times that of lead)... 

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