Archive for the ‘Tin Alloys’ Category
Wednesday, January 2nd, 2008
In heat treating of tin-rich alloys, it is difficult to secure an effective and permanent degree of hardening. Tin melts at 232°C (505 K), and therefore room temperature (about 295 K) is well over one-half the absolute melting point. It follows that high-temperature behavior such as recrystallization and recovery can ...
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Wednesday, September 19th, 2007
In this study, (100)-orientation silicon wafer coated with TiN barrier is catalyzed by a Pd/Sn colloid, which serves as an activator for electroless copper deposition. After activation, electroless deposition of Cu occurs on the catalytic surface. The coverage of the Cu deposit reaches 100% and the adsorptive amount of Pd ...
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Wednesday, September 19th, 2007
Cubic boron nitride (CBN) coating, due to its promising properties, is under development worldwide for machining and other related applications. To synthesize a continuous CBN coating by conventional vapor deposition methods (CVD/PVD), however, poses many challenges, such as metastable CBN phase stabilization, as well as the high levels of intrinsic ...
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Wednesday, September 19th, 2007
The interfacial intermetallics between Cu and solder were studied for four Sn-Pb compositions at the annealing temperatures of 125[degrees]C, 150[degrees]C, and 175[degrees]C for up to 30 days. The [eta]-phase (Cu^sub 6^Sn^sub 5^) layer formed during reflow continues to grow during annealing. An additional layer of [varepsilon]-phase (Cu^sub 3^Sn) forms at ...
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Saturday, July 21st, 2007
Jitterbugging flecks of metal are challenging some prevailing ideas of how alloys form.
When deposited atop a pure copper crystal, tin atoms form into 100,000-atom rafts that scoot around madly, depositing bronze spots in their wake, physicists at Sandia National Laboratories in Livermore, Calif., have found.
So much for the long-held notion ...
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Saturday, July 21st, 2007
Solder joints were prepared from seven eutectic and near-eutectic Sn-based compositions and characterized for electrical resistivity after 100 h and 1,000 h of isothermal aging at 423 K. The solder joint samples were prepared by hand soldering to copper substrates, and the post-heat treatment resistivity was measured at room temperature ...
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Saturday, July 21st, 2007
The wetting of I-Ag (immersion silver) and I-Sn (immersion tin) printed-circuit-board (PCB) finishes by Sn/Ag/Cu and eutectic Sn/Pb solders was studied in this work with Ni/Au (electroless nickel/immersion gold) and organic solderability preservative (OSP) finishes as baselines. Wetting tests were performed on fresh boards and boards subjected to different preconditioning ...
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Saturday, July 21st, 2007
The microstructures from the reaction between Au and Sn under different conditions were studied. A Sn/Au/Ni sandwich structure (2.5/3.752 µm) was deposited over the Si wafer. The overall composition of the Au and Sn layers corresponded to the Au20Sn binary eutectic (wt.%). When the reaction condition was 290°C for 2 ...
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Saturday, July 21st, 2007
Metallurgical changes that have improved superalloys and titanium alloys--making the metal stronger, tougher and/or more resistant to oxidation or corrosion--have also made these metals more difficult to machine.
For the nickel-, iron- and cobalt-based superalloys, high temperature characteristics translate directly to machining challenges. The combination of high cutting force and high ...
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Monday, March 20th, 2006
In heat treating of tin-rich alloys, it is difficult to secure an effective and permanent degree of hardening. Tin melts at 232°C (505 K), and therefore room temperature (about 295 K) is well over one-half the absolute melting point. It follows that high-temperature behavior such as recrystallization ...
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