In situ measurement of silicon oxidation kinetics by monitoring spectrally emitted radiation

1987 ◽  
Vol 22 (10) ◽  
pp. 3595-3601 ◽  
Author(s):  
Gerhard H. Schiroky
Keyword(s):  
Oxidation Kinetics ◽  
In Situ Measurement ◽  
Silicon Oxidation

scholarly journals In situ investigation of mesoporous silicon oxidation kinetics using infrared emittance spectroscopy

2016 ◽  
Vol 18 (27) ◽  
pp. 18201-18208 ◽  
Author(s):  
Benjamin Bardet ◽  
Domingos De Sousa Meneses ◽  
Thomas Defforge ◽  
Jérôme Billoué ◽  
Gaël Gautier
Keyword(s):  
Oxidation Kinetics ◽  
Silicon Oxidation ◽  
Mesoporous Silicon ◽  
Chemical Mechanisms ◽  
In Situ Investigation ◽  
Kinetics Of

The kinetics of mesoporous silicon oxidation is investigated by means of infrared emittance measurements. The chemical mechanisms are put in perspective with temperature.

In Situ Measurement of Soil Heat Flux with the Gradient Method

2003 ◽  
Vol 2 (4) ◽  
pp. 589
Author(s):  
Douglas R. Cobos ◽  
John M. Baker
Keyword(s):  
Heat Flux ◽  
Gradient Method ◽  
Soil Heat Flux ◽  
In Situ Measurement

In-Situ Measurement Technique of Stress and Structure Change

2015 ◽  
Vol 84 (8) ◽  
pp. 567-572
Author(s):  
Tadafumi HASHIMOTO ◽  
Masahito MOCHIZUKI
Keyword(s):  
Measurement Technique ◽  
Structure Change ◽  
In Situ Measurement

scholarly journals In situ measurement and closed-loop control for powder supply processes

2021 ◽  
Author(s):  
Philipp Peter Breese ◽  
Tobias Hauser ◽  
Daniel Regulin ◽  
Stefan Seebauer ◽  
Christian Rupprecht
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Closed Loop ◽  
In Situ Measurement ◽  
Closed Loop Control ◽  
Loop Control ◽  
Powder Feeder ◽  
Powder Mass

AbstractThe powder mass flow rate is one of the main parameters regarding the geometrical precision of built components in the additive manufacturing process of laser metal deposition. However, its accuracy, constancy, and repeatability over the course of the running process is not given. Reasons among others are the performance of the powder conveyors, the complex nature of the powder behavior, and the resulting issues with existing closed-loop control approaches. Additionally, a direct in situ measurement of the powder mass flow rate is only possible with intrusive methods. This publication introduces a novel approach to measure the current powder mass flow rate at a frequency of 125 Hz. The volumetric powder flow evaluation given by a simple optical sensor concept was transferred to a mass flow rate through mathematical dependencies. They were found experimentally for a nickel-based powder (Inconel 625) and are valid for a wide range of mass flow rates. With this, the dynamic behavior of a vibration powder feeder was investigated and a memory effect dependent on previous powder feeder speeds was discovered. Next, a closed-loop control with the received sensor signal was implemented. The concept as a whole gives a repeatable and accurate powder mass flow rate while being universally retrofittable and applicable. In a final step, the improved dynamic and steady performance of the powder mass flow rate with closed-loop control was validated. It showed a reduction of mean relative errors for step responses of up to 81% compared to the uncontrolled cases.

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