Direct Fabrication of IC Sacrificial Patterns via Rapid Prototyping Approaches

2012 ◽  
Vol 6 (5) ◽  
pp. 570-575 ◽  
Author(s):  
Omar Mohd Faizan Marwah ◽  
◽  
Safian Sharif ◽  
Mustaffa Ibrahim ◽  
Keyword(s):  
Thermal Analysis ◽  
Rapid Prototyping ◽  
Decomposition Temperature ◽  
Ceramic Shell ◽  
Internal Structures ◽  
Direct Fabrication ◽  
Abs Pattern ◽  
Routine Handling ◽  
Residual Ash ◽  
Resistance To Heat

Patterns made from conventional wax materials in the Investment Casting (IC) process can easily be distorted, damaged, or broken in transportation or routine handling or due to exposure to heat. Alternatively, the strength and toughness of most Rapid Prototyping (RP) materials virtually eliminates this drawback due to their resistance to heat, humidity, and post curing. The current study is conducted to investigate the feasibility of using RP processes such as FDM and MJM to fabricate IC patterns from Acrylonitrile Butadine Styrene (ABS) and acrylate based materials respectively to be used directly in IC process. Evaluation of the effects of different internal pattern designs of the RP parts are conducted based on the thermal analysis approach and burnout properties of the RP patterns. Ceramic shell molds are fabricated on both RP patterns and subsequently placed in an oven which is gradually heated to 1000°C. The decomposition temperature and the residual ash of the RP pattern materials is determined and analyzed. Results show that the acrylate pattern ofMJMdecomposes rapidly compared to the ABS pattern from the FDM process. It is also observed that quasi and square hollow internal structures show better collapsibility or burnout properties, with no cracks, compared to cross pattern and cross hatch designs.

scholarly journals Preparation of Few-Layered WS2 and Its Thermal Catalysis for Dihydroxylammonium-5,5′-Bistetrazole-1,1′-Diolate

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Yiping Shang ◽  
Wu Yang ◽  
Yabei Xu ◽  
Siru Pan ◽  
Huayu Wang ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Analysis Data ◽  
Decomposition Temperature ◽  
Thermal Excitation ◽  
Layered Semiconductor ◽  
Initial Decomposition Temperature ◽  
Thermal Decomposition Behavior ◽  
Decomposition Behavior ◽  
Catalytic Effects

In this study, few-layered tungsten disulfide (WS2) was prepared using a liquid phase exfoliation (LPE) method, and its thermal catalytic effects on an important kind of energetic salts, dihydroxylammonium-5,5′-bistetrazole-1,1′-diolate (TKX-50), were investigated. Few-layered WS2 nanosheets were obtained successfully from LPE process. And the effects of the catalytic activity of the bulk and few-layered WS2 on the thermal decomposition behavior of TKX-50 were studied by using synchronous thermal analysis (STA). Moreover, the thermal analysis data was analyzed furtherly by using the thermokinetic software AKTS. The results showed the WS2 materials had an intrinsic thermal catalysis performance for TKX-50 thermal decomposition. With the few-layered WS2 added, the initial decomposition temperature and activation energy (Ea) of TKX-50 had been decreased more efficiently. A possible thermal catalysis decomposition mechanism was proposed based on WS2. Two dimensional-layered semiconductor WS2 materials under thermal excitation can promote the primary decomposition of TKX-50 by enhancing the H-transfer progress.

scholarly journals The influence of VO2(B) nanobelts on thermal decomposition of ammonium perchlorate

2015 ◽  
Vol 33 (3) ◽  
pp. 560-565 ◽  
Author(s):  
Yifu Zhang ◽  
Xianfang Tan ◽  
Changgong Meng
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Ammonium Perchlorate ◽  
Vanadium Dioxide ◽  
Thermo Gravimetric Analysis ◽  
Great Influence ◽  
Decomposition Temperature ◽  
Gravimetric Analysis ◽  
Thermal Decomposition Temperature ◽  
Thermo Gravimetric

Abstract The influence of vanadium dioxide VO2(B) on thermal decomposition of ammonium perchlorate (AP) has not been reported before. In this contribution, the effect of VO2(B) nanobelts on the thermal decomposition of AP was investigated by the Thermo- Gravimetric Analysis and Differential Thermal Analysis (TG/DTA). VO2(B) nanobelts were hydrothermally prepared using peroxovanadium (V) complexes, ethanol and water as starting materials. The thermal decomposition temperatures of AP in the presence of I wt.%, 3 wt.% and 6 wt.% of as-obtained VO2<B) nanobelts were reduced by 39 °C. 62 °C and 74 °C, respectively. The results indicated that VO2(B) nanobelts had a great influence on the thermal decomposition temperature of AP Furthermore, the influence of the corresponding V2Os, which was obtained by thermal treatment of VO2(B) nanobelts, on the thermal decomposition of AP was also investigated. The resufs showed that VO2(B) nanobelts had a greater influence on the thermal decomposition temperature of AP than that of V2Os.

Synthesis and characterization of the pentazolate anion cyclo-N5ˉ in (N5)6(H3O)3(NH4)4Cl

Science ◽  
2017 ◽  
Vol 355 (6323) ◽  
pp. 374-376 ◽  
Author(s):  
Chong Zhang ◽  
Chengguo Sun ◽  
Bingcheng Hu ◽  
Chuanming Yu ◽  
Ming Lu
Keyword(s):  
Thermal Analysis ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Decomposition Temperature ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Onset Decomposition Temperature ◽  
The Stability

Pentazole (HN5), an unstable molecular ring comprising five nitrogen atoms, has been of great interest to researchers for the better part of a century. We report the synthesis and characterization of the pentazolate anion stabilized in a (N5)6(H3O)3(NH4)4Cl salt. The anion was generated by direct cleavage of the C–N bond in a multisubstituted arylpentazole using m-chloroperbenzoic acid and ferrous bisglycinate. The structure was confirmed by single-crystal x-ray diffraction analysis, which highlighted stabilization of the cyclo-N5ˉ ring by chloride, ammonium, and hydronium. Thermal analysis indicated the stability of the salt below 117°C on the basis of thermogravimetry-measured onset decomposition temperature.

scholarly journals Preparation and Thermal Analysis of Blended Nanoaluminum/Fluorinated Polyether-Segmented Urethane Composites

2019 ◽  
Vol 3 (1) ◽  
pp. 25 ◽  
Author(s):  
Chance Baxter ◽  
Jena McCollum ◽  
Scott Iacono
Keyword(s):  
Thermal Analysis ◽  
Thermal Characterization ◽  
Decomposition Temperature ◽  
Thermally Induced ◽  
Low Surface Energy ◽  
Characterization Study ◽  
Thermal Data ◽  
Processing Techniques ◽  
Solvent Processing ◽  
Induced Reaction

The thermally induced reaction of aluminum fuel and a fluoropolymer oxidizer such as polytetrafluoroethylene (via C-F activation) has been a well-studied thermite event for slow-burning pyrolants among a multitude of energetic applications. Generally, most metallized thermoplastic fluoropolymers suffer from manufacturing limitations using common melt or solvent processing techniques due to the inherent low surface energy and high crystallinity of fluoropolymers. In this report, we prepared an energetic composite utilizing the versatility of urethane-based polymers and provide a comparative thermal characterization study. Specifically, a thermite formulation comprising of nanometer-sized aluminum (nAl) fuel coated with perfluoropolyether (PFPE) oxidizer was solvent-blended with either a polyethylene glycol (PEG) or PFPE-segmented urethane copolymer. Thermal data were collected with calorimetric and thermogravimetric techniques to determine glass transition temperature and decomposition temperature, which showed modest effects upon various loadings of PFPE-coated nAl in the urethane matrix. While our application focus was for energetics, this study also demonstrates the potential to expand the ability to broadly manufacture structural metallized composites to their consideration as coatings, foams, or fibers.

ANNEALING AND PHOTOINDUCED EFFECTS IN ELECTROCHEMICALLY SYNTHESIZED Hg-1212 FILMS

2005 ◽  
Vol 19 (27) ◽  
pp. 4021-4046
Author(s):  
D. D. SHIVAGAN ◽  
P. M. SHIRAGE ◽  
S. H. PAWAR ◽  
TANAY SETH ◽  
D. P. AMALNERKAR
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Annealing Temperature ◽  
Thermo Gravimetric Analysis ◽  
Decomposition Temperature ◽  
Gravimetric Analysis ◽  
Thermal Decomposition Temperature ◽  
Superconducting Properties ◽  
Thermo Gravimetric ◽  
Flowing Oxygen

The thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA) of the as-deposited and electrochemically oxidized Hg 1 Ba 2 Ca 1 Cu 2 O 6+δ( Hg -1212) samples were carried out in air, flowing oxygen and nitrogen environment in order to estimate the thermal decomposition temperature and hence to maintain the annealing temperature and atmosphere. After annealing, electrochemically synthesized films showed an increase in Tc from 104.7 K to 119 K and Jc values from 1.43×103 to 4.3×103 A/cm 2. Electrochemically oxidized Hg -1212 films in under-, optimally- and over-doped states were irradiated with a Red He – Ne laser (2mW) and the Tc was found to increase from 104.7 K to 106 K and Jc from 1.43×103 to 1.89×103 A/cm 2. The effects of annealing and photo-irradiation on structural, microstructural and superconducting properties of electrochemically synthesized Hg-1212 films were investigated and discussed in detail in this paper.

Thermal Analysis of Halide Activator Used in Aluminizing of TiAl Intermetallics

2013 ◽  
Vol 592-593 ◽  
pp. 473-476
Author(s):  
Kamil Dychtoń ◽  
Roman Przeliorz ◽  
Marek Góral ◽  
Jan Sieniawski
Keyword(s):  
Thermal Analysis ◽  
Suitable Condition ◽  
Decomposition Temperature ◽  
Growth Behavior ◽  
Enthalpy Change ◽  
Chloride Salt ◽  
Vapor Species ◽  
Tial Intermetallics ◽  
Partial Pressures ◽  
Analytical Tools

A detailed study of thermal analysis of ZrCl4 was carried out to investigate the influence of the halide salt type activator on the growth behavior of coating formed in vapor phase aluminizing process and subsequently to identify the most suitable condition. The equilibrium partial pressures of vapor species generated at the decomposition temperature of ZrCl4 were calculated by using a procedure based on minimization of the whole Gibbs energy with Factsage 6.2 using Fact 53 and SGsold thermodynamic databases. The results were discussed and compared with literatures. With the aid of thermodynamic analytical tools, chloride salt activator was analysed and the decomposition temperature with related enthalpy change was evaluated.

Thermal analysis of layer formation in a stepless rapid prototyping process

2004 ◽  
Vol 24 (2-3) ◽  
pp. 255-268 ◽  
Author(s):  
Wenbin Hong ◽  
Yong Tsui Lee ◽  
Haiqing Gong
Keyword(s):  
Thermal Analysis ◽  
Rapid Prototyping ◽  
Layer Formation
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