Diagnostics of chip formation and surface quality by parameters of the main drive current in the hard turning

2019 ◽  
Vol 19 ◽  
pp. 1845-1851
Author(s):  
Dmitriy Rastorguev ◽  
Alexander Sevastyanov
2020 ◽  
Vol 15 ◽  
Author(s):  
Lei Li ◽  
Yujun Cai ◽  
Guohe Li ◽  
Meng Liu

Background: As an important method of remanufacturing, laser cladding can be used to obtain the parts with specific shapes by stacking materials layer by layer. The formation mechanism of laser cladding determines the “Staircase effect”, which makes the surface quality can hardly meet the dimensional accuracy of the parts. Therefore, the subsequent machining must be performed to improve the dimensional accuracy and surface quality of cladding parts. Methods: In this paper, chip formation, cutting force, cutting temperature, tool wear, surface quality, and optimization of cutting parameters in the subsequent cutting of laser cladding layer are analyzed. Scholars have expounded and studied these five aspects but the cutting mechanism of laser cladding need further research. Results: The characteristics of cladding layer are similar to that of difficult to machine materials, and the change of parameters has a significant impact on the cutting performance. Conclusion: The research status of subsequent machining of cladding layers is summarized, mainly from the aspects of chip formation, cutting force, cutting temperature, tool wear, surface quality, and cutting parameters optimization. Besides, the existing problems and further developments of subsequent machining of cladding layers are pointed out. The efforts are helpful to promote the development and application of laser cladding remanufacturing technology.


1999 ◽  
Vol 121 (2) ◽  
pp. 163-172 ◽  
Author(s):  
A. Vyas ◽  
M. C. Shaw

The saw-tooth chip was the last of the major types to be identified. This occurred in 1954 during machining studies of titanium alloys which were then being considered for aerospace applications because of their large strength-to-weight ratio and corrosion resistance. This is a type of chip that forms when very hard brittle materials are machined at high speeds and feeds. Since this is an area of machining which will be of increasing interest in the future, particularly in hard turning, it is important that the mechanism and mechanics of this type of chip formation be better understood. At present, there are two theories concerning the basic origin of saw-tooth chips. The first to appear assumed they are of thermal origin while the second assumes they arise due to the periodic development of cracks in the original surface of the work. The thesis presented here is that the root cause for saw-tooth chip formations is cyclic cracking. This is followed by a discussion of extensive experimental data that supports this point of view.


Author(s):  
Chetan Darshan ◽  
Lakhvir Singh ◽  
APS Sethi

Manufacturers around the globe persistently looking for the cheapest and quality manufactured machined components to compete in the market. Good surface quality is desired for the proper functioning of the produced parts. The surface quality is influenced by cutting speed, feed rate and depth of cut and many other parameters. In the present study attempt has been made to evaluate the performance of ceramic inserts during hard turning of EN-31 steel. The analysis of variance is applied to study the effect of cutting speed, feed rate and depth of cut on Flank wear and surface roughness. Model is found to be statically significant using regression model, while feed and depth of cut are the factor affecting Flank wear and feed is dominating factors for surface roughness. The analysis of variance was used to analyze the input parameters and there interactions during machining. The developed model predicted response factor at 95% confidence level.


Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2036 ◽  
Author(s):  
Adel T. Abbas ◽  
Magdy M. El Rayes ◽  
Monis Luqman ◽  
Noha Naeim ◽  
Hussien Hegab ◽  
...  

This article reports an experimental assessment of surface quality generated in the precision turning of AISI 4340 steel alloy using conventional round and wiper nose inserts for different cutting conditions. A three-factor (each at 4 levels) full factorial design of experiment was followed for feed rate, cutting speed, and depth of cut, with resulting machined surface quality characterized by resulting average roughness (Ra). The results show that, for the provided range of cutting conditions, lower surface roughness values were obtained using wiper inserts compared with conventional inserts, indicating a superior performance. When including the type of insert as a qualitative factor, ANOVA revealed that the type of insert was most important in determining surface roughness and material removal rate, with feed rate as the second most significant, followed by the interaction of feed rate and type of insert. It was found that using wiper inserts allowed simultaneous increases in feed rate, cutting speed, and depth of cut, while providing better surface quality of lower Ra, compared to the global minimum value that could be achieved using the conventional insert. These findings show that wiper inserts produce better surface quality and a material removal rate up to ten times higher than that obtained with conventional inserts. This clearly indicates the tremendous advantages of high surface quality and productivity that wiper inserts can offer when compared with the conventional round nose type in precision hard turning of AISI 4340 alloy steel.


Author(s):  
Елена Лагунова ◽  
Elena Lagunova

The paper reports the description of cutting problems connected with surface quality at chip formation. There is developed a bench for computer diagnostics of a cutting process at composite planning. In the course of investigations there was adduced a hypothesis of elastic deformation at composite cutting. A procedure is presented on the basis of a diagnostic center use. The results of the experimental investigations of chip formation dynamics and machining quality are obtained. The experimental investigations in the SAE program on composite deformation during chip formation at jointing are carried out. The diagrams of dependences and descriptions of conclusions, recommendations and conclusions on the use of SAE programs and a computer diagnostic center are obtained.


2020 ◽  
Vol 110 (11-12) ◽  
pp. 806-810
Author(s):  
Sebastian Berger ◽  
Jannis Saelzer ◽  
Dirk Biermann

Dieser Beitrag stellt die simulative Analyse zum Einfluss eines begrenzenden Elements zur Unterdrückung der Segmentspanbildung bei der Zerspanung der Titanlegierung Ti6Al4V vor. Dabei lässt sich aufzeigen, dass eine spanbildungsinduzierte periodische Anregung des Systems durch die geeignete Wahl von Geometrie und Positionierung des Elementes verhindert werden kann, wodurch sich die Werkzeugstandzeit und die Oberflächenqualität verbessern und schwingungsdämpfende Maßnahmen obsolet werden. This paper presents the simulative analysis of the influence of a counter element for the suppression of segmented chip formation during the machining of titanium alloy Ti6Al4V. It is shown that a chip formation induced periodic excitation of the system can be prevented by a suitable choice of geometry and positioning of the element, leading to increased tool life and surface quality as well as making vibration damping methods obsolete.


Author(s):  
Linwen Li ◽  
Bin Li ◽  
Xiaochun Li ◽  
Kornel F. Ehmann

Temperature-distribution measurements in cutting tools during the machining process are extremely difficult and remain an unresolved problem. In this paper, cutting temperature distributions are measured by thin film thermocouples (TFTCs) embedded into Polycrystalline Cubic Boron Nitride (PCBN) cutting inserts in the immediate vicinity of the tool-chip interface. Using these measurements, steady and dynamic phenomena during hard turning as well as the chip morphology and formation process were analyzed based on the cutting temperature distributions in the insert. The relationship between the cutting temperature-field distributions in the PCBN insert and the segmented chip formation is analyzed using temperature-distribution mapping. It is shown that the temperature-distribution in the cutting zone depends on the shearing band distribution in the chip and the thermal transfer rate from the heat generation zone to the cutting tool. Furthermore, it became evident that the material flow stress and the shearing bands greatly affect not only the chip formation morphology but also the cutting temperature field distributions in the cutting zone of the cutting insert.


2017 ◽  
Vol 39 (4) ◽  
pp. 251-258
Author(s):  
T. Zhao ◽  
M. Agmell ◽  
J. Persson ◽  
V. Bushlya ◽  
J. E. Ståhl ◽  
...  

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