Lost Wax Casting Conditions with Tourmaline In Situ

2017 ◽  
Vol 737 ◽  
pp. 595-598
Author(s):  
Kageeporn Wongpreedee ◽  
Adiruj Peerawat ◽  
Bongkot Phichaikamjornwut ◽  
Duangkhae Bootkul
Keyword(s):  
High Temperature ◽  
Ion Implantation ◽  
High Stability ◽  
High Hardness ◽  
Casting Process ◽  
Casting Condition ◽  
Precious Stones

The technique of stone-in-place casting has been established in jewelry production for three decades. However, the process is not widely used since it is limited to precious stones with high hardness and high stability at high temperature. This experiment tested tourmaline, which is a semi-precious gemstone having less hardness and less stability compared with precious stones. The objective was to achieve the conditions of a lost-wax casting process with tourmaline placed in waxes in the casting process. The experiment was divided into two parts. The first part was to understand the tolerance of tourmaline under the heating conditions. Natural tourmaline stones were investigated and compared inclusions tested at a temperature of 700°C. Tourmaline with ion-implantation was also heated to 700°C for comparison. The second part was to test tourmaline in-place casting with tree conditions of flask casting at 550°C, 625°C, and 700°C. The results showed that stones were able to tolerate as much as at 700°C. The inclusion growth of ion-implantation under heating to 700°C also observed the growth of inclusion in the same way as untreated tourmaline. The casting condition at 550°C showed better results. The highest probability of stones breaking after casting occurred in bezel settings.

scholarly journals Nanoscaled eutectic NiAl-(Cr,Mo) composites with exceptional mechanical properties processed by electron beam melting

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Andreas Förner ◽  
S. Giese ◽  
C. Arnold ◽  
P. Felfer ◽  
C. Körner ◽  
...  
Keyword(s):  
Electron Beam ◽  
High Temperature ◽  
Electron Beam Melting ◽  
Lamellar Microstructure ◽  
High Hardness ◽  
Additive Process ◽  
In Situ Composites ◽  
Selective Electron Beam Melting ◽  
Very High

Abstract Eutectic NiAl-(Cr,Mo) composites are promising high temperature materials due to their high melting point, excellent oxidation behavior and low density. To enhance the strength, hardness and fracture toughness, high cooling rates are beneficial to obtain a fine cellular-lamellar microstructure. This can be provided by the additive process of selective electron beam melting. The very high temperature gradient achieved in this process leads to the formation of the finest microstructure that has ever been reported for NiAl-(Cr,Mo) in-situ composites. A very high hardness and fracture toughening mechanisms were observed. This represents a feasibility study towards additive manufacturing of eutectic NiAl-(Cr,Mo) in-situ composites by selective electron beam melting.

High-temperature high-resolution in-situ microscopy of grain boundary migration and structure change

1990 ◽  
Vol 48 (4) ◽  
pp. 514-515
Author(s):  
Hideki Ichinose ◽  
Tokuji Kizuka ◽  
Yoichi Ishida
Keyword(s):  
High Temperature ◽  
High Resolution ◽  
Grain Boundary ◽  
High Stability ◽  
Boundary Migration ◽  
Structure Change ◽  
Objective Lens ◽  
Video Tape ◽  
Grain Boundary Migration

A high resolution high temperature specimen stage of 200kV HRTEM was newly designed and produced in order to investigate the physical and mechanical nature of materials at high temperature.The atomic process of silicon grain boundary migration and the structure change was successfully observed in-situ at 1000K by the new specimen stage.The high temperature specimen stage consists of a heating specimen holder, a high stability power supply and a high stability current controller. Heat is provided by an induction free double spiral coil heater which is made of tungsten. Excellent current stability, better than 10−6 , prevents the objective lens from the magnetic disturbance which is caused by heating current. The highest temperature of the specimen is designed to be 1100K. The accuracy of the temperature measurement is checked by the melting test of tin. In order to keep the high resolution of the microscope(JEM-200CX) at such high temperature as 1100K an objective lens is also newly designed and produced. Aberration constants of the new lens are respectively Cs=0.7mm and Cc=1.2mm. Resulted resolution at high temperature is as same level as the that of the original JEM-200CX at room temperature. Images are recorded by a video tape recorder.

scholarly journals Influence of the Casting Process in High Temperature Fatigue of A319 Aluminium Alloy Investigated By In-Situ X- Ray Tomography and Digital Volume Correlation

2016 ◽  
Vol 2 ◽  
pp. 3057-3064 ◽  
Author(s):  
Nora Dahdah ◽  
Nathalie Limodin ◽  
Ahmed El Bartali ◽  
Jean-François Witz ◽  
Rian Seghir ◽  
...  
Keyword(s):  
High Temperature ◽  
Aluminium Alloy ◽  
Casting Process ◽  
Digital Volume Correlation ◽  
X Ray ◽  
High Temperature Fatigue

Preparation of TiC/ Fe Surface Composite by a Casting–SHS Process

2008 ◽  
Vol 373-374 ◽  
pp. 666-669
Author(s):  
B.S. Jin ◽  
Y.F. Jiao ◽  
G. Li
Keyword(s):  
Surface Layer ◽  
High Temperature ◽  
Casting Process ◽  
Temperature Synthesis ◽  
Surface Composite ◽  
High Temperature Synthesis ◽  
Steel Castings ◽  
Sand Mould ◽  
Ceramic Reinforcement

Steel castings with a ceramic reinforced surface layer have been prepared by a casting process combined with self-propagation high-temperature synthesis (SHS). Two material systems, Fe-Ti-C-Al and Al-Fe2O3, were selected in this paper to prepare the steel castings with a ceramic reinforced surface layer. During the process, high temperature steel melt was poured into a sand mould in which SHS performs were cast. The performs were ignited by the high temperature steel melt. As a result, an SHS reaction happened and ceramic reinforcements were synthesized inside the mould. After the penetration of the molten steel and the scattering of the ceramic reinforcement, a steel casting with an in-situ ceramic reinforced surface layer was obtained.

Dynamic studies of silicide-mediated crystallization of amorphous silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1352-1353
Author(s):  
C. Hayzelden ◽  
J. L. Batstone
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Metallic Phase ◽  
Single Crystal Substrate ◽  
Free Electrons ◽  
Melt Temperature ◽  
Transmission Electron ◽  
Crystal Substrate ◽  
High Resolution Tem

Epitaxial reordering of amorphous Si(a-Si) on an underlying single-crystal substrate occurs well below the melt temperature by the process of solid phase epitaxial growth (SPEG). Growth of crystalline Si(c-Si) is known to be enhanced by the presence of small amounts of a metallic phase, presumably due to an interaction of the free electrons of the metal with the covalent Si bonds near the growing interface. Ion implantation of Ni was shown to lower the crystallization temperature of an a-Si thin film by approximately 200°C. Using in situ transmission electron microscopy (TEM), precipitates of NiSi2 formed within the a-Si film during annealing, were observed to migrate, leaving a trail of epitaxial c-Si. High resolution TEM revealed an epitaxial NiSi2/Si(l11) interface which was Type A. We discuss here the enhanced nucleation of c-Si and subsequent silicide-mediated SPEG of Ni-implanted a-Si.Thin films of a-Si, 950 Å thick, were deposited onto Si(100) wafers capped with 1000Å of a-SiO2. Ion implantation produced sharply peaked Ni concentrations of 4×l020 and 2×l021 ions cm−3, in the center of the films.

The reaction of amorphous Ni-Nb films with Si in the presence of a native SiO2 layer

1990 ◽  
Vol 48 (4) ◽  
pp. 664-665
Author(s):  
N. Rozhanski ◽  
A. Barg
Keyword(s):  
High Temperature ◽  
Crystallization Temperature ◽  
Diffusion Barriers ◽  
Sio2 Layer ◽  
Si Substrate ◽  
Cross Sectional ◽  
Plan View ◽  
Temperature Range ◽  
Sputter Deposited

Amorphous Ni-Nb alloys are of potential interest as diffusion barriers for high temperature metallization for VLSI. In the present work amorphous Ni-Nb films were sputter deposited on Si(100) and their interaction with a substrate was studied in the temperature range (200-700)°C. The crystallization of films was observed on the plan-view specimens heated in-situ in Philips-400ST microscope. Cross-sectional objects were prepared to study the structure of interfaces.The crystallization temperature of Ni5 0 Ni5 0 and Ni8 0 Nb2 0 films was found to be equal to 675°C and 525°C correspondingly. The crystallization of Ni5 0 Ni5 0 films is followed by the formation of Ni6Nb7 and Ni3Nb nucleus. Ni8 0Nb2 0 films crystallise with the formation of Ni and Ni3Nb crystals. No interaction of both films with Si substrate was observed on plan-view specimens up to 700°C, that is due to the barrier action of the native SiO2 layer.

REYNOLDS 390 and A390

Alloy Digest ◽  
1971 ◽  
Vol 20 (8) ◽  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
High Hardness ◽  
Heat Treating ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Temperature Performance

Abstract REYNOLDS 390 and A390 are hypereutectic aluminum-silicon alloys having excellent wear resistance coupled with good mechanical properties, high hardness, and low coefficients of expansion. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, and machining. Filing Code: Al-203. Producer or source: Reynolds Metals Company.

DURATECH 30

Alloy Digest ◽  
2006 ◽  
Vol 55 (3) ◽  
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
High Hardness ◽  
Heat Treating ◽  
Powder Metal ◽  
Temperature Performance ◽  
Very High

Abstract DuraTech 30 is a superhigh-speed steel evolved from the ASTM M3-2 composition, but with added cobalt. The exotic composition offers improved toughness and very high hardness. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on high temperature performance and wear resistance as well as heat treating, machining, and powder metal forms. Filing Code: TS-629. Producer or source: Timken Latrobe Steel.

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