Combined X-ray diffraction and photothermal radiometry methods for in situ analysis of nitriding treatment

2018 ◽  
Vol 115 (4) ◽  
pp. 408
Author(s):  
Juan Dong ◽  
Jeremy Epp ◽  
Robin Lipinski ◽  
Michael Sorg ◽  
Hans-Werner Zoch ◽  
...  
Keyword(s):  
Surface State ◽  
Photothermal Radiometry ◽  
Monitoring And Control ◽  
X Ray Diffraction ◽  
X Ray ◽  
Combined Application ◽  
Process Monitoring And Control ◽  
Aisi H13 ◽  
And Control

Monitoring the nitriding treatment by analyzing directly the components’ surface state during the nitriding treatment is particularly interesting, since it allows a process monitoring and control based on the actual nitriding result. In the present study, two measuring methods are developed and combined with the aim of a direct surface state analysis during the nitriding treatment: the in situ X-ray diffraction (XRD) method and the photothermal radiometry. In order to validate the combined application of both methods during a nitriding treatment under controlled atmosphere, an experimental setup including a miniature nitriding furnace was developed. Two alloyed steels AISI 4140 and AISI H13 are treated with varying process atmosphere and nitriding potential leading to varying phase composition in the surface layer. As a result, the photothermal radiometry is shown to be sensitive with respect to the changing surface properties due to the growing compound layers and when porous layers are generated. It has a high potential to serve as surface sensor in industrial processes.

scholarly journals Correlation Between Insulation Resistance and Temperature Measurement Error in Type K and Type N Mineral Insulated, Metal Sheathed Thermocouples

2022 ◽  
Vol 43 (3) ◽  
Author(s):  
Jonathan Pearce ◽  
Declan Tucker ◽  
Carmen García Izquierdo ◽  
Raul Caballero ◽  
Trevor Ford ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Measurement Errors ◽  
Insulation Resistance ◽  
Monitoring And Control ◽  
Type K ◽  
Reference Type ◽  
Process Monitoring And Control ◽  
Resistance Breakdown ◽  
And Control

AbstractMineral insulated, metal sheathed (MI) Type K and Type N thermocouples are widely used in industry for process monitoring and control. One factor that limits their accuracy is the dramatic decrease in the insulation resistance at temperatures above about 600 °C which results in temperature measurement errors due to electrical shunting. In this work the insulation resistance of a cohort of representative MI thermocouples was characterised at temperatures up to 1160 °C, with simultaneous measurements of the error in indicated temperature by in situ comparison with a reference Type R thermocouple. Intriguingly, there appears to be a systematic relationship between the insulation resistance and the error in the indicated temperature. At a given temperature, as the insulation resistance decreases, there is a corresponding increasingly negative error in the temperature measurement. Although the measurements have a relatively large uncertainty (up to about 1 °C in temperature error and up to about 10 % in insulation resistance measurement), the trend is apparent at all temperatures above 600 °C, which suggests that it is real. Furthermore, the correlation disappears at temperatures below about 600 °C, which is consistent with the well-established diminution of insulation resistance breakdown effects below that temperature. This raises the intriguing possibility of using the as-new MI thermocouple calibration as an indicator of insulation resistance breakdown: large deviations of the electromotive force (emf) in the negative direction could indicate a correspondingly low insulation resistance.

scholarly journals Controlled sample environment for studying solid–gas interactions by in situ powder X-ray diffraction

2021 ◽  
Vol 54 (1) ◽  
pp. 371-375
Author(s):  
Paul Monceyron Røren ◽  
Kristoffer W. B. Hunvik ◽  
Vegard Josvanger ◽  
Ole Tore Buseth ◽  
Jon Otto Fossum
Keyword(s):  
Applied Pressure ◽  
Copper Plate ◽  
Temperature Control System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Custom Made ◽  
Quartz Capillary ◽  
Gas Interactions ◽  
And Control

A sample cell for powder X-ray diffraction studies with in situ applied pressure and control of temperature is demonstrated. The cell is based on a previously reported design and consists of a glass or quartz capillary glued into a Swagelok weld gland; this configuration can hold up to 100 bar (1 bar = 100 kPa). The cell is placed in contact with a copper plate for control of temperature between −30 and 200°C. This is achieved by Peltier elements, heat cartridges and a refrigerated circulating bath. This work mainly focuses on the temperature control system. Commissioning tests were performed in a custom-made small/wide-angle X-ray diffractometer at the Norwegian University of Science and Technology. The system is easily portable to synchrotron facilities.

Viewport Influence on Optical Pyrometry and Deposition Process in Mocvd Vertical Rotating Disc Reactors

1999 ◽  
Vol 588 ◽  
Author(s):  
Anton Prokopenko ◽  
Alexander Gurary ◽  
Vadim Boguslavskiy ◽  
Jeffrey Ramer ◽  
Matthew Schurman
Keyword(s):  
Deposition Process ◽  
Operating Conditions ◽  
Flow Dynamics ◽  
Monitoring And Control ◽  
Rotating Disc ◽  
Process Monitoring And Control ◽  
Purge Flow ◽  
Reactor Operating ◽  
And Control

AbstractOptical access to the wafer for the in-situ process monitoring and control is a requirement for the advanced MOCVD equipment. Depending on their location and design, viewports can affect the reactor flow dynamics and temperature distribution inside the growth chamber thus ultimately affecting the deposition process. Furthermore, deposition on the viewport can influence the accuracy of in-situ measurements.We have investigated viewport influence on the MOCVD vertical rotating disc reactors manufactured by EMCORE Corporation. Viewport transmittance was established for different conditions and viewport types. Computational fluid dynamics was utilized to establish conditions at which viewport has no considerable influence on deposition results. The validity of model predictions was verified by examining the results of actual deposition runs on the reactor. We have demonstrated that under typical EMCORE reactor operating conditions, viewports presence on the reactor inlet flange and a purge flow through it have minimal effect on the reactor flow dynamics and ultimately on material growth rate and thickness uniformity.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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