Bronze weight

An example where one metal melts before the densihcation process, is the formation of bronze from a 90 10 weight percentage mixture of copper and tin. The tin melts at a temperature of 505 K, and the liquid immediately wets the copper particles, leaving voids in the compact. The tin then diffuses into the copper particles, leaving further voids due to dre Kirkendall effect. The compact is therefore seen to swell before the hnal sintering temperature of 1080 K is reached. After a period of homogenization dictated by tire criterion above, the alloy shrinks on cooling to leave a net dilatation on alloy formation of about 1%. 

In the so-called Dormagen process developed by IG Farben the cotton was first preheated with 30-40% of its own weight with glacial acetic acid for 1-2 hours. The pretreated material was then fed to the acetylisers, which consisted of horizontal bronze cylinders. For every 100 parts of pretreated cellulose there was added the following acetylating mixture, previously cooled to 15-20°C ... 

The domestic use pattern for lead in 1990 was as follows lead-acid storage batteries, used for motor vehicles, motive power, and emergency back-up power, accounted for 80% of total lead consumption ammunition, bearing metals, brass and bronze, cable covering, extruded products, sheet lead, and solder, represented 12.4% the remaining 7.6% was used for ceramics, type metal, ballast or weights, tubes or containers, oxides, and gasoline additives (USDOC 1992). 

Golden obtained polymeric materials with molecular weights up to 1800 from potassium />-chlorophenoxide in refluxing nitrobenzene as solvent in the presence of copper bronze as catalyst (28). 

Many methods are available for determining particle size in pharmaceutical practice, including microscopy, sieving, sedimentation, and determination of particle volume [19]. Sieve analysis with U.S. standard sieves is widely used to determine the particle size distribution based on powder weight. Sieves are classified according to the number of openings (Table 14) and are generally made of wire cloth woven from brass, bronze, or other suitable wire. 

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