On the Fundamental Mechanism of Large Strain Plastic Deformation: Electron Microscopy of Metal Cutting Chips

1971 ◽  
Vol 93 (2) ◽  
pp. 507-526 ◽  
Author(s):  
J. T. Black
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
Metal Cutting ◽  
Large Strain ◽  
Cutting Parameters ◽  
Machining Process ◽  
Aluminum Chips ◽  
Shear Front ◽  
Microscopy Techniques ◽  
Fundamental Mechanism

The process of large strain plastic deformation, such as commonly found in the machining process, has been investigated by transmission and scanning electron microscopy techniques. The lamella-shear front nature of deformation in copper and aluminum chips has been elucidated fully and the occurrence of lamellae has been correlated with crystallographic and metal cutting parameters.

Shear Front-Lamella Structure in Large Strain Plastic Deformation Processes

1972 ◽  
Vol 94 (1) ◽  
pp. 307-313 ◽  
Author(s):  
J. T. Black
Keyword(s):  
Electron Microscopy ◽  
Plastic Deformation ◽  
Large Strain ◽  
Machining Processes ◽  
Fundamental Understanding ◽  
Deformation Processes ◽  
Copper Aluminum ◽  
Shear Front ◽  
Lamella Structure ◽  
Scanning Electron

The examination of the surface morphology of copper, aluminum, and steel chips produced by standard shop machining processes through the use of scanning electron microscopy has led to a more fundamental understanding of large strain plastic deformation processes. The interpretation of these findings is discussed in terms of well documented dislocation mechanisms typically associated with tensile and compression deformation of metal crystals. The effect that such investigations will have on the true understanding of the mechanisms involved in plastic deformation processes is noted.

Temperature Field Numerical Analysis of Machining Process Based on the Finite Element Analysis

2014 ◽  
Vol 621 ◽  
pp. 611-616 ◽  
Author(s):  
Yan Juan Hu ◽  
Yao Wang ◽  
Zhan Li Wang
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Cutting Temperature ◽  
Cutting Parameters ◽  
Element Model ◽  
Machining Process ◽  
Element Analysis ◽  
Mechanical Coupling

In order to study the temperature field distribution in the process of machining, the finite element theory was used to establish the orthogonal cutting finite element model, and the key technologies were discussed simultaneously. By using ABAQUS software for cutting AISI1045 steel temperature field of numerical simulation, the conclusion about changing rule of cutting temperature field can be gotten. The results show that this method can efficiently simulate the distribution of temperature field of the workpiece, cutter and scraps, which is effected by thermo-mechanical coupling in metal work process. It provides the theory evidence for the intensive study of metal-cutting principle, optimizing cutting parameters and improving processing technic and so on.

Influence of Cutting Conditions on Surface and Sub-Surface Quality of High Speed Dry End Milling Ti-6Al-4V

2014 ◽  
Vol 67 (3) ◽  
Author(s):  
H. Safari ◽  
S. Izman
Keyword(s):  
Plastic Deformation ◽  
Tool Wear ◽  
Surface Quality ◽  
High Speed ◽  
End Milling ◽  
Cutting Parameters ◽  
Machining Process ◽  
Surface Alteration ◽  
Cutting Speeds

Surface quality is one of the most critical restraints for determining cutting parameters and selecting of machining process in metal cutting process. In this study, the effects of cutting parameters and tool wear on the surface and sub-surface quality of high speed dry end milling Ti-6Al-4V were investigated. PVD Coated carbide tools were used under different high cutting speeds and feed rates. The quality of the machined surface and corresponding alteration on the sub-surface and entry/exit edges were characterized through scanning electron microscopy. The results showed that the better surface quality was obtained when machining at higher cutting speeds and feed rates. High speed dry end milling using the worn tool causes to plastic deformation of the alloy which is resulted in developing the lamellae on the surface and causing poor surface finish. Worn tools with the uniform tool wear land generated better surface quality compare to those with chipping and flaking on the tool edge surface. Tool wear is suggested as the other contributing factor in developing entry and exit edge damages. The results of sub-surface alteration measurement revealed that the worn tool enhanced the sub-surface alteration resulted in 45% increase in plastic deformation compare to the new tool.

scholarly journals The Effect of the Feed Direction on the Micro- and Macro Accuracy of 3D Ball-end Milling of Chromium-Molybdenum Alloy Steel

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4038
Author(s):  
Balázs Mikó ◽  
Bálint Varga ◽  
Wojciech Zębala
Keyword(s):  
Surface Roughness ◽  
Metal Cutting ◽  
Tool Path ◽  
End Milling ◽  
Cutting Parameters ◽  
Machining Process ◽  
Free Form ◽  
Dimensional Error ◽  
Ball End Milling ◽  
Free Form Surfaces

The machining of free form surfaces is one of the most challenging problems in the field of metal cutting technology. The produced part and machining process should satisfy the working, accuracy, and financial requirements. The accuracy can describe dimensional, geometrical, and surface roughness parameters. In the current article, three of them are investigated in the case of the ball-end milling of a convex and concave cylindrical surface form 42CrMo4 steel alloy. The effect of the tool path direction is investigated and the other cutting parameters are constant. The surface roughness and the geometric error are measured by contact methods. Based on the results, the surface roughness, dimensional error, and the geometrical error mean different aspects of the accuracy, but they are not independent from each other. The investigated input parameters have a similar effect on them. The regression analyses result a very good liner regression for geometric errors and shows the importance of surface roughness.

Dry Machining of T6061 Aluminium Alloy Using Titanium Carbonitride (TiCN) Coated Tools

2013 ◽  
Vol 652-654 ◽  
pp. 2129-2133
Author(s):  
Tasnim Firdaus Ariff ◽  
Nur Najwa Sofian ◽  
Nor Hayati Che Mat
Keyword(s):  
Metal Cutting ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Machining Process ◽  
Titanium Carbonitride ◽  
Cutting Fluids ◽  
Dry Machining ◽  
Coated Tools ◽  
Percentage Difference ◽  
Optimum Cutting

In metal cutting process, the use of cutting fluids, cooling and easy chip removal causes long-term effects of cutting fluids disposal into environment. Research has also proven the health hazards on manufacturing workers who coming in direct contact with cutting fluids. Currently it is highly competitive or end-user of metal workings fluid to reduce cost and improve productivity. Considering the high cost and problems associated with health and safety, it would be desirable if the use of cutting fluids be omitted. This study investigates the flank wear behavior of coated Titanium Carbonitride (TiCN) coated tools in dry and wet machining of T6061 Aluminum alloy with the aim of obtaining the optimum cutting speed for dry and wet machining respectively. By using specific depths of cut 0.2 and 0.6 mm with feed rates of 0.4 and 0.8 mm/rev respectively, the wear was investigated for 3 different high cutting speeds; 290, 360 and 446 mm/min. Results of dry machining was compared with traditional wet machining process. The temperature of tool tip, machining time and tool wear were recorded. Wear rate of the tool increases with the increasing cutting speed and parameters for both dry and wet machining. Wear percentage difference for dry machining was found to be 21-37 % (d = 0.2 mm and f = 0.4 mm/rev) and 41 - 58% (d = 0.6 mm and f = 0.8 mm/rev) higher than wet machining. The optimum cutting speed for both cutting parameters is 446 m/min for dry and wet machining. Tool tip temperature for dry machining is found to be 14 - 16 % higher than wet machining for both cutting parameters. It is observed that dry machining is suitable for high speed intermittent cutting operations.

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