Experimental Research of Pneumatic Drop-on-Demand High Temperature Droplet Deposition for Rapid Prototyping

2009 ◽  
Vol 419-420 ◽  
pp. 405-408 ◽  
Author(s):  
Xiang Hui Zeng ◽  
Le Hua Qi ◽  
Hua Huang ◽  
Xiao Shan Jiang ◽  
Yuan Xiao
Keyword(s):  
Melting Point ◽  
Rapid Prototyping ◽  
Oxygen Content ◽  
Vertical Direction ◽  
Metal Droplet ◽  
High Melting ◽  
Droplet Deposition ◽  
High Melting Point ◽  
On Demand ◽  
Drop On Demand

Generating high-melting-point metals droplet is a bottleneck in the area of droplet-based rapid prototyping. In our research, a pneumatic drop-on-demand (DOD) generator was developed which can spray A2024 alloy successfully, and the maximum ejection temperature can reach to 1200°C. Experiments were conducted to examine the influence of the oxygen content on the metal droplet spray. The uniform A2024 droplet was ejected stably under the condition where the oxygen content was less than 25ppm. As the solenoid valve was opened once with different time span, four cases were observed: droplet stream, three droplets, two droplets and one single droplet. A2024 droplets were deposited continuously on top of each other in vertical direction to form vertical columns, which meant the graphite nozzle can be used in experiment. A simple square tube was produced by regulating the droplet generator, which showed the rapid prototyping by high-melting-point droplet deposition is feasible.

Parameters Study on Generation of Uniform Copper Droplet by Pneumatic Drop-on-Demand Technology

2012 ◽  
Vol 430-432 ◽  
pp. 781-784 ◽  
Author(s):  
Song Yi Zhong ◽  
Le Hua Qi ◽  
Jun Luo ◽  
Yuan Xiao
Keyword(s):  
Melting Point ◽  
Droplet Size ◽  
Pulse Width ◽  
High Melting ◽  
Droplet Generator ◽  
High Melting Point ◽  
On Demand ◽  
Drop On Demand ◽  
The Stability ◽  
Deposition Technology

Studying on the mechanism and device for high-melting-point metals droplets deposition technology are imperfect. In our research, a pneumatic driven droplet generator was developed to generate mono-sized copper droplets. Experiments were conducted to investigate the influence of spray pressure and pulse width on the size of droplets. Droplet was stably ejected while spray pressure was between 30kPa and 35kPa and pulse width was between 600μs and 900μs. The droplet size increased as the spray pressure increased. However the pulse width had no significant impact on the droplet size. At last a copper column was fabricated to certify the stability of the system and the reproducibility of the parameters.

Numerical Simulation on Deposition and Solidification Processes of a Molten Metal Droplet Generated by Drop-on-Demand Jetting

2012 ◽  
Vol 538-541 ◽  
pp. 890-894 ◽  
Author(s):  
Peng Yun Wang ◽  
He Jun Li ◽  
Le Hua Qi ◽  
Hai Liang Deng ◽  
Han Song Zuo
Keyword(s):  
Numerical Simulation ◽  
Substrate Temperature ◽  
Metal Droplet ◽  
Dimensional Accuracy ◽  
Droplet Deposition ◽  
On Demand ◽  
Drop On Demand ◽  
Solidification Processes ◽  
Droplet Spray ◽  
Uniform Droplet

Droplet deposition and solidification is vital to dimensional accuracy and mechanical properties of components prepared by uniform droplet spray (UDS) forming. In this paper, a volume-of-fluid (VOF) based model was developed to study the deposition and solidification processes of a 1 mm Al-4.5%Cu droplet generated by drop-on-demand jetting. The effects of droplet falling velocity (0.6-0.8 m/s), initial temperature (933-973 K), and substrate temperature (300-473 K) were investigated. The results show that the final morphology of the deposited droplet is largely dependent on falling velocity and substrate temperature. The solidified droplet obtained from an UDS experiment validates the numerical simulation.

CRM MOLYBDENUM-50 RHENIUM

Alloy Digest ◽  
1970 ◽  
Vol 19 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Melting Point ◽  
Physical Properties ◽  
Heat Treating ◽  
Electrical Contacts ◽  
High Melting ◽  
High Melting Point ◽  
Temperature Performance

Abstract CRM MOLYBDENUM-50 RHENIUM is a high-melting-point alloy for applications such as electronics tube components, electrical contacts, thermionic converters, thermocouples, heating elements and rocket thrusters. All products are produced by powder metallurgy. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Mo-11. Producer or source: Chase Brass & Copper Company Inc..

CRM RHENIUM

Alloy Digest ◽  
1970 ◽  
Vol 19 (8) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Melting Point ◽  
Heat Treating ◽  
Electrical Contacts ◽  
High Melting ◽  
High Melting Point ◽  
Temperature Performance ◽  
Commercially Pure

Abstract CRM RHENIUM is a commercially pure, high-melting-point metal for applications such as electronics tube components, electrical contacts, thermionic converters, thermocouples, heating elements and rocket thrusters. All products are produced by powder metallurgy. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Re-1. Producer or source: Chase Brass & Copper Company Inc..

WIELAND DURO TUNGSTEN

Alloy Digest ◽  
2020 ◽  
Vol 69 (10) ◽  
Keyword(s):  
Melting Point ◽  
Physical Properties ◽  
Tensile Properties ◽  
Modulus Of Elasticity ◽  
Radiation Shielding ◽  
High Melting ◽  
High Modulus ◽  
High Melting Point ◽  
Structural Applications ◽  
Very High

Abstract Wieland Duro Tungsten is unalloyed tungsten produced from pressed-and-sintered billets. The high melting point of tungsten makes it an obvious choice for structural applications exposed to very high temperatures. Tungsten is used at lower temperatures for applications that can benefit from its high density, high modulus of elasticity, or radiation shielding capability. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on machining. Filing Code: W-34. Producer or source: Wieland Duro GmbH.

Facile synthesis of high‐melting point spherical TiC and TiN powders at low temperature

2019 ◽  
Vol 103 (2) ◽  
pp. 889-898 ◽  
Author(s):  
Maoqiao Xiang ◽  
Miao Song ◽  
Qingshan Zhu ◽  
Chaoquan Hu ◽  
Yafeng Yang ◽  
...  
Keyword(s):  
Melting Point ◽  
Low Temperature ◽  
High Melting ◽  
High Melting Point ◽  
Facile Synthesis

Screening of high melting point phase change materials (PCM) in solar thermal concentrating technology based on CLFR

Solar Energy ◽  
2005 ◽  
Vol 79 (3) ◽  
pp. 332-339 ◽  
Author(s):  
Akira Hoshi ◽  
David R. Mills ◽  
Antoine Bittar ◽  
Takeo S. Saitoh
Keyword(s):  
Melting Point ◽  
Phase Change ◽  
Phase Change Materials ◽  
Solar Thermal ◽  
High Melting ◽  
High Melting Point

Observation of Rheed Intensity Oscillations During PbSe/CaF2/Si(111) MBE

1996 ◽  
Vol 441 ◽  
Author(s):  
W. K. Liu ◽  
X. M. Fang ◽  
P. J. McCann ◽  
M. B. Santos
Keyword(s):  
Activation Energy ◽  
Melting Point ◽  
Substrate Temperature ◽  
High Melting ◽  
Arrhenius Behavior ◽  
High Activation ◽  
High Melting Point ◽  
Mbe Growth ◽  
Sublimation Energy ◽  
Initial Nucleation

AbstractRHEED intensity oscillations observed during MBE growth of CaF2 on Si(111) and PbSe on CaF2/Si(111) are presented. The effects of substrate temperature and initial nucleation procedure are investigated. Strong temporal oscillations of the specular beam intensity are found to be most readily observed at temperatures below 200°C for both CaF2 and PbSe. Growth rates measured as a function of cell temperatures exhibit Arrhenius behavior with activation energies of 5.0 eV and 1.93 eV for CaF2 and PbSe, respectively. The relatively high activation energy obtained for CaF2 is consistent with the high melting point and sublimation energy of ionic fluorides.

A study of pest oxidation in polycrystalline MoSi2

1992 ◽  
Vol 7 (10) ◽  
pp. 2747-2755 ◽  
Author(s):  
C.G. McKamey ◽  
P.F. Tortorelli ◽  
J.H. DeVan ◽  
C.A. Carmichael
Keyword(s):  
High Temperature ◽  
Melting Point ◽  
Stoichiometric Ratio ◽  
Low Density ◽  
High Melting ◽  
Phase Boundaries ◽  
High Melting Point ◽  
Good Oxidation Resistance ◽  
Intermediate Temperature Range ◽  
Physical Defects

MoSi2 is a promising high-temperature material with low density (6.3 g/cm3), high melting point (2020 °C), and good oxidation resistance at temperatures to about 1900 °C. However, in the intermediate temperature range between 400 and 600 °C, it is susceptible to a “pest” reaction which causes catastrophic disintegration by a combination of oxidation and fracture. In this study, we have used polycrystalline MoSi2, produced by arc-casting of the pure elements and by cold and hot pressing of alloy powders, to characterize the pest reaction and to determine the roles of composition, grain or phase boundaries, and physical defects on the oxidation and fracture of specimens exposed to air at 500 °C. It was found that pest disintegration occurs through transport of oxygen into the interior of the specimen along pre-existing cracks and/or pores, where it reacts to form MoO3 and SiO2. The internal stress produced during the formation of MoO3 results in disintegration to powder. Near the stoichiometric ratio, the susceptibility to pest disintegration increases with increasing molybdenum content and with decreasing density. Silicon-rich alloys were able to form protective SiO2 and showed no indication of disintegration, even at densities as low as 60%.

Processing of Zinc-Based MgAl2O4 Composite and Effect of Fly Ash Addition

2007 ◽  
Vol 336-338 ◽  
pp. 1203-1206 ◽  
Author(s):  
Metin Gürü ◽  
M. Korçak ◽  
Süleyman Tekeli ◽  
Ahmet Güral
Keyword(s):  
Tensile Strength ◽  
Fly Ash ◽  
Melting Point ◽  
Low Density ◽  
High Melting ◽  
Spinel Oxide ◽  
High Melting Point ◽  
Corrosion Resistant ◽  
Coal Power ◽  
Resistant Composite Material

The properties of ceramic-metal (Cermet) composites as tensile strength, hardness and resistance to corrosion and high temperature are superior than ceramics and metals. Because of the enhanced characteristics of cermets, they are commonly used in various applications and industries. The main objective of this study is to produce a cheap, easy produced, strong and high corrosion resistant composite material. For these purposes, zinc is used for its natural capacity against corrosion, low density, low melting point and softness. Magnesium aluminates spinel oxide (MgAl2O4) is chosen because of its high melting point and low density. Fly ash is a waste from coal power plant having puzzolanic properties. In this study, the effect of various amounts of zinc and fly ash addition on density and hardness behaviour of zinc-based MgAl2O4 composites was investigated. The experimental results showed that zinc and fly ash addition improved the hardness behavior of zincbased MgAl2O4 composite.

Sign in / Sign up

Export Citation Format

Share Document