EFFECT OF CRYSTALLOGRAPHIC ORIENTATION ON CUTTING FORCES AND SURFACE FINISH IN DUCTILE CUTTING OF KDP CRYSTALS

2011 ◽  
Vol 15 (2) ◽  
pp. 231-242 ◽  
Author(s):  
Haofeng Chen ◽  
Yifan Dai ◽  
Ziwen Zheng ◽  
Hang Gao ◽  
Xiaoping Li
2014 ◽  
Vol 984-985 ◽  
pp. 15-24 ◽  
Author(s):  
S. Srikiran ◽  
K. Ramji ◽  
B. Satyanarayana

The generation of heat during machining at the cutting zone adversely affects the surface finish and tool life. The heat at the cutting zone, which plays a negative role due to poor thermal conductivity, resistance to wear, high strength at high temperatures and chemical degradation can be overcome by the use of proper lubrication. Advancements in the field of tribology have led to the use of solid lubricants replacing the conventional flood coolants. This work involves the use of nanoparticulate graphite powder as a lubricant in turning operations whose performance is judged in terms of cutting forces, tool temperature and surface finish of the work piece. The experimentation revealed the increase in cutting forces and the tool temperature when the solid lubricant used is decreased in particle size. The surface finish deteriorated with the decrease in particle size of the lubricant in the nanoregime.Keywords-Turning, Solid lubricant, Graphite, Minimum Quantity Lubrication, nano–particles,Weight percentage,Frictioncoefficient.


2000 ◽  
Vol 122 (4) ◽  
pp. 384-388 ◽  
Author(s):  
Stuart Barnes ◽  
Ian R. Pashby

Through-tool coolant was applied to the drilling of an aluminum/SiC MMC. Titanium nitride coated, solid carbide drills were used to investigate the effect of the coolant application method on the performance of the drilling operation. Holes were produced dry, with conventional coolant and with through-the tool coolant. The results provided strong evidence that the conventional application of coolant was having no beneficial effect on the cutting operation compared to dry drilling. However, through-tool cooling gave a significant improvement in performance in terms of tool wear, cutting forces, surface finish and the height of the burrs produced. [S0094-4289(00)02104-6]


2015 ◽  
Vol 799-800 ◽  
pp. 361-365 ◽  
Author(s):  
Roshaliza Hamidon ◽  
Erry Y.T. Adesta ◽  
Muhammad Riza ◽  
Mohammad Iqbal

In machining operation of mould cavities, the tool travels in various straight and corner profiles following predetermined toolpath. Such condition results in a fluctuation of cutting forces that may produce bad surface finish. The objective of this study is to investigate the most influential parameters on cutting operation for both straight and corner profiles of pocketing operation. Cutting speeds of 150, 200 and 250m/min, feedrates from 0.05, 0.1, 0.15 mm/tooth and depths of cut of 0.1, 0.15 and 0.2 mm were selected for the cutting processes. Taguchi L9 orthogonal array with Pareto ANOVA analysis was employed to analyze the effects of the selected parameters. The result demonstrates there are different effects of cutting parameters on cutting forces for straight and corner profiles. Furthermore, it was found that cutting speed and feedrate are prevailing factors that affected cutting forces for both types of profile.


2021 ◽  
Author(s):  
António Festas ◽  
A. Ramos ◽  
J. P. Davim

Abstract The potential and advantages revealed by the application of 3D manufacturing techniques such as Electron Beam Melting (EBM) in the production of medical devices such as orthopaedic implants are increasing manly in custom made devices. However, the use of milling and turning operations are indispensable on surfaces where surface finish and dimensional accuracy have more demanding requirements. This work aims to evaluate the machinability of titanium alloy test samples submitted to turning operations, to obtain the geometry of a functional cone of the modular component of the hip prosthesis. The differences in cutting forces and surface finish obtained in the turning tests are compared between a wrought Ti-6Al-4V test sample and three obtained by EBM with different thicknesses. To perform the tests, a constant cutting speed of 60m/min was used, feed of 0.1 and 0.2mm/rev and ap of 0.15mm. The cutting forces were measured for each test, also the roughness was measured in the form of Ra, Rt and RzD in each test sample. From the results obtained, EBM test samples presented higher roughness values and lower resulting cutting forces. In both materials, the effect of feed rate is visible. When machining a cone, the passive force and the cutting force become the most influential forces. Generally, when the feed rate value was doubled, the resulting machining forces value increased up to about 50% for both types of materials and the Ra value to approximately 200%. The EBM technology as used form medical devices allow good quality surfaces as the wrought titanium alloy.


2014 ◽  
Vol 902 ◽  
pp. 267-273 ◽  
Author(s):  
Samir Mekid

The emerging miniaturized high-tech products are required to have increased functionalities of systems within a volumetric size on the order of 1 cm3. Hence, the parts are mesoscopic with complex microscopic features of a few mm length with machining accuracy of better than 1 micrometer with secured surface integrity as components will require high surface finish, tensile stress and crack free surfaces in order to function reliably. One of the characteristics to be measured is the cutting forces on the parts being machined. This paper will present the design, manufacture and testing of a miniature dynamometer capable of measuring cutting forces within a low range of 50N but with a resolution better than 1 mN and high frequency since the micromachining involves small cutting forces but the spindle rotates at high speed. The dynamometer is capable of measuring forces in five directions (±x, ±y, and z). The instrument was calibrated and exhibit very good results leading to a true validation. This instrument is assembled on a micro milling desktop machine designed in-house. It will not only support predicting the surface finish and chip thickness but also monitoring tool wear evolution and hence prevents/reduce tool breakage known to be one of the main issues in micro-milling.


Wear ◽  
2004 ◽  
Vol 257 (7-8) ◽  
pp. 751-759 ◽  
Author(s):  
M. Sharif Uddin ◽  
K.H.W. Seah ◽  
X.P. Li ◽  
M. Rahman ◽  
K. Liu

Author(s):  
Dilbag Singh ◽  
P. Venkateswara Rao

In hard turning, lot of heat is generated due to plastic deformation of the work material, friction at the tool-chip interface and friction between tool and the workpiece. The heat produced in machining adversely affects the quality of the products produced. Cutting fluids have been the conventional choice to deal with this problem. However, due to the environmental restrictions, the use of cutting fluids is restricted. Machining with solid lubricants, cryogenic cooling by liquid nitrogen and minimum quantity lubrication are some of the alternative approaches in this direction. This research work deals with an investigation on using molybdenum disulphide as solid lubricant in order to reduce friction for improving the machining performance and for overcoming some of the limitations that arise due to the use of cutting fluids or while dry hard turning. An experimental setup has been designed and built, and experiments have been conducted to study the effect of using molybdenum disulphide as solid lubricant on surface finish and cutting forces. An improvement in surface finish was observed with molybdenum disulphide assisted hard turning. It was also observed that there was a considerable reduction of cutting forces, thereby reducing the specific energy needed and consequently improving the machining performance.


Author(s):  
Sape A. Miedema

Merchant (1944), (1945A) and (1945B) derived a model for determining the cutting forces when machining steel. The model was based on elastic-plastic deformation and a continuous chip formation (ductile cutting). The model included internal and external friction and shear strength, but no adhesion, gravity, inertia and pore pressures. Later Miedema (1987 September) extended this model with adhesion, gravity, inertial forces and pore water pressures. These models however only describe the so called Flow Type of cutting process, which is the ductile cutting process. The ductile cutting process requires a relatively large tensile strength (BTS) compared to the compressive strength (UCS) or shear strength. If the tensile strength is not large enough, brittle failure based on tensile failure may occur. This paper describes a new method of determining the cutting forces resulting from brittle failure, still based on the original ductile models, but with a correction for the stresses. This new model can be used for Deep Sea Mining Applications. It is assumed that materials which behave brittle under atmospheric conditions will behave ductile under hyperbaric conditions.


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