In-process and ex-situ measurement techniques for the characterization of surface conditions during cryogenic hard turning of AISI 52100

2020 ◽  
Vol 87 (11) ◽  
pp. 694-703
Author(s):  
Julian Uebel ◽  
Werner Ankener ◽  
Stephan Basten ◽  
Marek Smaga ◽  
Benjamin Kirsch ◽  
...  
Keyword(s):  
Surface Layer ◽  
Hard Turning ◽  
Feedforward Control ◽  
Measurement Techniques ◽  
Hardness Measurement ◽  
Ex Situ ◽  
Measurement Technology ◽  
Aisi 52100 ◽  
The One ◽  
Turned Parts

AbstractThe surface layer states of a component are of great importance for the application of hard turned parts. Without a multitude of tests and experience, the states cannot be reliably produced due to process-typical disturbance variables such as tool wear and batch inclusions. The aim of this research is to control the surface layer states during cryogenic hard turning of AISI 52100 by feedforward control and the use of a soft sensor. This paper presents the measurement techniques used in this context. On the one hand, the in-process measurement technology and challenges involved are discussed. On the other hand, the challenges in the ex-situ measurement technique for characterizing the surface layer states are shown using micro hardness measurement as an example.

On Predicting Softening Effects in Hard Turned Surfaces—Part I: Construction of Material Softening Model

2004 ◽  
Vol 127 (3) ◽  
pp. 476-483 ◽  
Author(s):  
Jing Shi ◽  
C. Richard Liu
Keyword(s):  
Thermal History ◽  
Hard Turning ◽  
Hardness Measurement ◽  
Average Error ◽  
Suitable Model ◽  
Material Microstructure ◽  
Average Prediction Error ◽  
Aisi 52100 ◽  
Finishing Process ◽  
Aisi 52100 Steel

The need for predicting material microstructure and hardness in hard turned surfaces becomes very urgent in that hard turning is adopted by industries as a finishing process, and the produced surface integrity, including microstructure and hardness, is well known to be a determining factor for part service performance. This study focuses on the prediction of material softening and is composed of two parts, namely, the construction of material softening model based on thermal history and the prediction of thermal history by finite element modeling of hard turning. In this part of the research, three material softening models based on thermal activation concept are proposed and compared. The most suitable model is selected for the work material, hardened AISI 52100 steel. The model prediction demonstrates excellent agreement with the hardness measurement on the specimens with isothermal or anisothermal treatments. For the isothermal treatments, the average prediction error, compared with the measured hardness, is 10.78kg∕mm2. As for the anisothermal treatments, the average error is 13.79kg∕mm2. The softening model provides a fundamental for the final prediction of material softening in hard turned surfaces.

scholarly journals Validation of the TOLNet Lidars: The Southern California Ozone Observation Project (SCOOP)

2018 ◽  
Author(s):  
Thierry Leblanc ◽  
Mark A. Brewer ◽  
Patrick S. Wang ◽  
Maria Jose Granados-Munoz ◽  
Kevin B. Strawbridge ◽  
...  
Keyword(s):  
Tropospheric Ozone ◽  
Southern California ◽  
Measurement Techniques ◽  
Reference Network ◽  
Control Effort ◽  
The North ◽  
Lidar Measurements ◽  
Spatio Temporal ◽  
To Come ◽  
The One

Abstract. The North-America-based Tropospheric Ozone Lidar Network (TOLNet) was recently established to provide high spatio-temporal vertical profiles of ozone, to better understand physical processes driving tropospheric ozone variability, and to validate the tropospheric ozone measurements of upcoming space-borne missions such as Tropospheric Emissions: Monitoring Pollution (TEMPO). The network currently comprises six tropospheric ozone lidars, four of which are mobile instruments deploying to the field a few times per year, based on campaign and science needs. In August 2016, all four mobile TOLNet lidars were brought to the fixed TOLNet site of JPL-Table Mountain Facility for the one-week-long Southern California Ozone Observation Project (SCOOP). This inter-comparison campaign, which included 400 hours of lidar measurements and 18 ozonesondes launches, allowed for the unprecedented simultaneous validation of five of the six TOLNet lidars. For measurements between 3 and 10 km above sea level, a mean difference of 0.7 ppbv (1.7 %), with a root-mean-square deviation of 1.6 ppbv or 2.4 % was found between the lidars and ozonesondes, which is well within the combined uncertainties of the two measurement techniques. The few minor differences identified were typically associated with the known limitations of the lidars at the profiles altitude extremes (i.e., first 1 km above ground and at the instruments highest retrievable altitude). As part of a large homogenization and quality control effort within the network, many aspects of the TOLNet in-house data processing algorithms were also standardized and validated. This thorough validation of both the measurements and retrievals builds confidence in the high quality and reliability of the TOLNet ozone lidar profiles for many years to come, making TOLNet a valuable ground-based reference network for tropospheric ozone profiling.

scholarly journals Machining force comparison for surface defect hard turning and conventional hard turning of AISI 52100 steel

2021 ◽  
Vol 13 (3) ◽  
pp. 205-214
Author(s):  
P. U MAMAHESWARRAO ◽  
D. RANGARAJU ◽  
K. N. S. SUMAN ◽  
B. RAVISANKAR
Keyword(s):  
Hard Turning ◽  
Surface Defect ◽  
Cutting Speed ◽  
Tool Geometry ◽  
Depth Of Cut ◽  
Nose Radius ◽  
Aisi 52100 ◽  
Machining Force ◽  
Aisi 52100 Steel ◽  
The Impact

In this article, a recently developed method called surface defect machining (SDM) for hard turning has been adopted and termed surface defect hard turning (SDHT). The main purpose of the present study was to explore the impact of cutting parameters like cutting speed, feed, depth of cut, and tool geometry parameters such as nose radius and negative rake angle of the machining force during surface defect hard turning (SDHT) of AISI 52100 steel in dry condition with Polycrystalline cubic boron nitride (PCBN) tool; and results were compared with conventional hard turning (CHT). Experimentation is devised and executed as per Central Composite Design (CCD) of Response Surface Methodology (RSM). Results reported that an average machining force was decreased by 22% for surface defect hard turning (SDHT) compared to conventional hard turning (CHT).

Erfahrungen mit alternativen Kraftmessungen/Experiences with alternative force measurements - Comparing sensor-integrated toolholders to traditional piezo-based measurement technology

2020 ◽  
Vol 110 (01-02) ◽  
pp. 24-31
Author(s):  
Patrick Georgi ◽  
Ssrah Eschelbacher ◽  
Thomas Stehle ◽  
Hans-Christian Möhring
Keyword(s):  
Cutting Force ◽  
Force Measurement ◽  
Milling Process ◽  
The Other ◽  
Strain Gauges ◽  
Measurement Technology ◽  
Optimal Parameters ◽  
Force Measurements ◽  
Measuring Systems ◽  
The One

Die Prozessüberwachung spielt in der Zerspanung eine immer wichtiger werdende Rolle. So können zum Beispiel mittels Zerspankraftmessungen ökonomisch optimierte Parameter in Zerspanprozessen gefunden werden, die zu einer Verbesserung der Auslastung von Werkzeug und Maschine führen. Des Weiteren kann über die Zerspankraft auf den aktuellen Verschleißzustand der Werkzeuge im Prozess sowie auf die jeweils erreichbare Bearbeitungsgenauigkeit zurückgeschlossen werden. Für Zerspankraftmessungen gibt es eine Vielzahl an zur Verfügung stehenden Kraftmesssystemen; zum einen traditionelle Messtechnik auf Basis von Piezosensoren zur Kraftmessung und zum anderen Kraftmesstechnik auf der Basis von Dehnmessstreifen (DMS). Dieser Beitrag untersucht die Kraftaufnahme bei Fräs- und Bohrprozessen, bei denen beide Kraftmesssysteme simultan eingesetzt wurden.   Process monitoring plays an increasingly important role in machining. For example, through cutting force measurements, it is possible to find economically optimal parameters in the milling process, which lead to an improvement in the utilization of the tool and the machine. Furthermore, the cutting force can be used to deduce the state of wear of the tools in the process. There are varieties of available force measuring systems for this purpose; on the one hand, traditional measuring technology based on piezo sensors for force measurement and the other force measuring technology based on strain gauges (strain gauges). This article examines the force absorption in milling and drilling processes where both force-measuring systems were used simultaneously.

Effect of Cutting-Edge Geometry and Workpiece Hardness on Surface Residual Stresses in Finish Hard Turning of AISI 52100 Steel

1999 ◽  
Author(s):  
Jeffrey D. Thiele ◽  
Shreyes N. Melkote ◽  
Roberta A. Peascoe ◽  
Thomas R. Watkins
Keyword(s):  
Residual Stresses ◽  
Hard Turning ◽  
Cutting Edge ◽  
Phase Changes ◽  
Edge Geometry ◽  
Surface Residual Stresses ◽  
Aisi 52100 ◽  
High Feed ◽  
Aisi 52100 Steel ◽  
Finish Hard Turning

Abstract An experimental investigation was conducted to determine the effects of tool cutting-edge geometry and workpiece hardness on surface residual stresses for finish hard turning of through-hardened AISI 52100 steel. Polycrystalline cubic boron nitride (PCBN) inserts with representative types of edge geometry including “up-sharp” edges, edge hones, and chamfers, were used as the cutting tools in this study. This study shows that tool edge geometry is highly influential with respect to surface residual stresses, which were measured using x-ray diffraction. In general, compressive surface residual stresses in the axial and circumferential directions were generated by large edge hone tools, for longitudinal turning operations. Residual stresses in the axial and circumferential directions generated by small edge hone tools are typically more tensile than stresses produced by large edge hone tools. Microstructural analysis shows that thermal effects are significant at high feed rates, based on the presence of phase changes on the workpiece surface. At high feed rates, compressive stresses correlate with continuous white layers and tensile stresses correlate with over-tempered regions on the surface of the workpiece. Mechanical effects play a larger role at low feed rates, where phase changes are not observed to a significant degree. For these cases, large edge hone tools generally produce more compressive values of residual stress than small edge hone tools.

The effect of boundaries on wave propagation in a liquid-filled porous solid: VI. Love waves in a double surface layer

1964 ◽  
Vol 54 (1) ◽  
pp. 417-423
Author(s):  
H. Deresiewicz
Keyword(s):  
Wave Propagation ◽  
Surface Layer ◽  
Dispersion Relation ◽  
Energy Loss ◽  
Classical Solution ◽  
Specific Energy ◽  
Classical Case ◽  
Specific Energy Loss ◽  
Double Surface ◽  
The One

abstract The classical solution of Stoneley and Tillotson is generalized by considering the outer one of the pair of layers to be porous. Although the dispersion relation turns out, for practical purposes, to be identical with the one governing the classical case, the motion in the present instance is shown to be dissipative and the expression is exhibited for the specific energy loss.

scholarly journals Comparison between Accelerometer and Laser Vibrometer to Measure Traffic Excited Vibrations on Bridges

2002 ◽  
Vol 9 (1-2) ◽  
pp. 11-18 ◽  
Author(s):  
G. Rossi ◽  
R. Marsili ◽  
V. Gusella ◽  
M. Gioffrè
Keyword(s):  
Modal Analysis ◽  
Measurement Techniques ◽  
Forced Vibrations ◽  
The Other ◽  
Laser Vibrometer ◽  
Threshold Parameter ◽  
Civil Structures ◽  
Low Frequencies ◽  
Acceleration Amplitude ◽  
The One

The use of accelerometer based measurement techniques for evaluating bridge forced vibrations or to perform bridge modal analysis is well established. It is well known to all researchers who have experience in vibration measurements that values of acceleration amplitude can be very low at low frequencies and that a limitation to the use of accelerometer can be due to the threshold parameter of this kind of transducer. Under this conditions the measurement of displacement seems more appropriate. On the other hand laser vibrometer systems detect relative displacements as opposed to the absolute measures of accelerometers. Vibrations have been measured simultaneously by a typical accelerometer for civil structures and by a laser vibrometer equipped with a fringe counter board in terms of velocity and displacements. The accelerations calculated from the laser vibrometer signals and the one directly measured by the accelerometer has been compared.

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