The lateral extrusion of copper pipes with a lost core of low temperature melting alloy

2001 ◽  
Vol 113 (1-3) ◽  
pp. 98-102 ◽  
Author(s):  
T Ohashi ◽  
K Matsui ◽  
Y Saotome
2012 ◽  
Vol 523-524 ◽  
pp. 1006-1011
Author(s):  
Takahiro Ohashi ◽  
Ngoquang Thanh ◽  
Ryosuke Miyajima

The authors have developed a lateral extrusion process with a lost core. The outline of the process is as follows. First, the cavity of a pipe, or a channel material, is filled up with liquid of a low-temperature melting material. The low-temperature melting material is then solidified to become a soluble core of the pipe. The authors call this soluble core the lost core. Next, the material is compressed longitudinally as a composite billet and extruded in the lateral direction. After deformation, the low-temperature melting material is melted and removed. The process can performed in a compression state to control the precise appearance of the product. This study examines a new core material, alumina powder (alumina ball) bonded with wax, as a core material. A mixing methodology for wax and alumina powder is discussed along with the effect of their mixing ratio on the deformation of the pipe.


2002 ◽  
Vol 51 (2) ◽  
pp. 111-116 ◽  
Author(s):  
Du??ke Dudi? ◽  
Du??an Kostoski ◽  
Vladimir Djokovi? ◽  
Miroslav D Drami?anin

2010 ◽  
Vol 434-435 ◽  
pp. 371-375
Author(s):  
Ming He ◽  
Shu Ren Zhang ◽  
Xiao Hua Zhou ◽  
Jian Geng Hu ◽  
Ting Zhang ◽  
...  

. A doping CaO-B2O3-SiO2 system low temperature co-fired ceramics (LTCC) was prepared with a mixture of high temperature melting glass and sol-gel glass for different ratio. The effects of sol-gel glass content on the microstructure, crystalline phases, sintering properties and dielectric properties of CaO-B2O3-SiO2 system were investigated at 850°C. The results show that the samples with sol-gel glass doping had little change in phase composition, but contained more calcium silicates, and less calcium borate. As the amount of sol-gel glass increased, the shrinkage improved, the sintered density slightly decreased, the dielectric constant (εr) reduced, and the dielectric loss (tgδ) decreased. When the amount of sol-gel glass was 14.5wt%, εr and tgδ of the doping sample were 5.80, 4.6×10-5 (at 1 MHz), respectively. Moreover, the doping system had a good matching ability with gold slurry and Au-Pt-Pd slurry.


2006 ◽  
Author(s):  
E. N. Redichev ◽  
D. G. Gromov ◽  
S. A. Gavrilov ◽  
A. I. Mochalov ◽  
R. M. Ammosov

2016 ◽  
Vol 703 ◽  
pp. 11-16 ◽  
Author(s):  
Takahiro Ohashi

This paper proposes a new filling material, fiber-reinforced ice (FRI), for tube bending. In tube bending, lead and low temperature melting alloys have conventionally been utilized as the filling medium to prevent defects and to alleviate flattening of the tube’s cross section. However, these alloys are usually harmful to the environment (e.g., Pb, Bi-Pb-Sn-In, or Pb-Cd system alloys) or are expensive (e.g., In-Sn system alloys). In this study, the author utilized ice reinforced with the fiber of wastepaper for 3-point bending of JIS G 3452 SGP 32A steel tubes. Compression tests were conducted to analyze whether these tubes have crushing strength comparable to that of conventional fillings and sufficient ductility in low-speed deformation. The filling medium with more fiber effectively yielded less flattening.


Geology ◽  
2021 ◽  
Author(s):  
Peng Gao ◽  
Chris Yakymchuk ◽  
Jian Zhang ◽  
Changqing Yin ◽  
Jiahui Qian ◽  
...  

Hafnium (Hf) isotopes in zircon are important tracers of granite petrogenesis and continental crust evolution. However, zircon in granites generally shows large Hf isotope variations, and the reasons for this are debated. We applied U-Pb geochronology, trace-element, and Hf isotope analyses of zircon from the Miocene Himalayan granites to address this issue. Autocrystic zircon had εHf values (at 20 Ma) of –12.0 to –4.3 (median = –9). Inherited zircon yielded εHf values (at 20 Ma) of –34.8 to +0.3 (median = –13); the majority of εHf values were lower than those of autocrystic zircon. The εHf values of inherited zircon with high U concentrations resembled those of autocrystic zircon. Geochemical data indicates that the granites were generated during relatively low-temperature (<800 °C) partial melting of metasedimentary rocks, which, coupled with kinetic hindrance, may have led to the preferential dissolution of high-U zircon that could dissolve more efficiently into anatectic melt due to higher amounts of radiation damage. Consequently, Hf values of autocrystic zircon can be biased toward the values of U-rich zircon in the source. By contrast, literature data indicate that granites generated at high temperatures (<820–850 °C) generally contain autocrystic and inherited zircons with comparable Hf isotope values. During higher-temperature melting, indiscriminate dissolution of source zircon until saturation is reached will result in near-complete inheritance of Hf isotope ratios from the source. Our results impose an extra layer of complexity to interpretation of the zircon Hf isotope archive that is not currently considered.


2006 ◽  
Author(s):  
D. G. Gromov ◽  
S. A. Gavrilov ◽  
E. N. Redichev ◽  
A. I. Mochalov ◽  
R. M. Ammosov

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