EVALUATION OF SURFACE ROUGHNESS PRODUCED BY NANOCUTTING COPPER STRUCTURE USING A LEAST SQUARE MEAN METHOD

2019 ◽  
Vol 27 (01) ◽  
pp. 1950081 ◽  
Author(s):  
CHUNHUI JI ◽  
SHUANGQIU SUN ◽  
BIN LIN ◽  
TIANYI SUI

This work performed molecular dynamic simulations to study the 2D profile and 3D surface topography in the nanometric cutting process. The least square mean method was used to model the evaluation criteria for the surface roughness at the nanometric scale. The result showed that the cutting speed was the most important factor influencing the spacing between the peaks, the sharpness of the peaks, and the randomness of the profile. The plastic deformation degree of the machined surface at the nanometric scale was significantly influenced by the cutting speed and depth of cut. The 2D and 3D surface roughness parameters exhibited a similar variation tendency, and the parameters Ra and Rq tended to increase gradually with an increase in the cutting speed and a decrease in the depth of cut. Finally, it is concluded that at the nanometric scale, the 3D surface roughness parameters could more accurately reflect the real surface characteristics than the 2D parameters.

2018 ◽  
Vol 1148 ◽  
pp. 109-114
Author(s):  
M. Balaji ◽  
C.H. Nagaraju ◽  
V.U.S. Vara Prasad ◽  
R. Kalyani ◽  
B. Avinash

The main aim of this work is to analyse the significance of cutting parameters on surface roughness and spindle vibrations while machining the AA6063 alloy. The turning experiments were carried out on a CNC lathe with a constant spindle speed of 1000rpm using carbide tool inserts coated with Tic. The cutting speed, feed rate and depth of cut are chosen as process parameters whose values are varied in between 73.51m/min to 94.24m/min, 0.02 to 0.04 mm/rev and 0.25 to 0.45 mm respectively. For each experiment, the surface roughness parameters and the amplitude plots have been noted for analysis. The output data include surface roughness parameters (Ra,Rq,Rz) measured using Talysurf and vibration parameter as vibration amplitude (mm/sec) at the front end of the spindle in transverse direction using single channel spectrum analyzer (FFT).With the collected data Regression analysis is also performed for finding the optimum parameters. The results show that significant variation of surface irregularities and vibration amplitudes were observed with cutting speed and feed. The optimum cutting speed and feed from the regression analysis were 77.0697m/min and 0.0253mm/rev. for the minimum output parameters. No significant effect of depth of cut on output parameters is identified.


2015 ◽  
Vol 809-810 ◽  
pp. 93-98
Author(s):  
Ionuţ Urzică ◽  
Ciprian Râznic ◽  
Mihai Apostol ◽  
Corina Mihaela Pavăl ◽  
Mihai Boca ◽  
...  

Frequently, on the drawings of mechanical parts, only indications concerning the surface roughness parameter Ra and, relatively rarely, the surface roughness parameter Rz are included. However, the study of the machined surface roughness highlights the necessity to use yet other surface roughness parameters, in order to have a clearer image on the state of the machined surface. Some other surface roughness parameters possible to be used and presenting importance, without the parameters Ra and Rz, were highlighted. One took into consideration the possibility of measuring parameters Rsk and Rmr by means of the available surface roughness testers. Experimental researches of turning by applying the method of full factorial experiment were developed. As input factors in turning process, the cutting speed, the feed rate and the tool nose radius were used. The experimental results were mathematically processed, being determined empirical mathematical models that highlight the influence of certain input factors of turning process on the values of some surface roughness parameters characterized by a more restricted use


2017 ◽  
Vol 7 (5) ◽  
pp. 2047-2055
Author(s):  
M. H. El-Axir ◽  
M. M. Elkhabeery ◽  
M. M. Okasha

The influence of some turning variables and tool overhang on surface roughness parameters and residual stress induced due to machining 6061-T6 aluminum alloy is investigated in this paper. Four input parameters (cutting speed, feed rate, depth of cut and tool overhang) are considered. Tests are carried out by precision turning operation on a lathe. Design of experiment techniques, i.e. response surface methodology (RSM) and Taguchi's technique have been used to accomplish the objective of the experimental study. Surface roughness parameters are measured using a portable surface roughness device while residual stresses are measured employing deflection-etching technique using electrochemical analysis. The results obtained reveal that feed and rotational speed play significant role in determining the average surface roughness. Furthermore, the depth of cut and tool overhang are less significant parameters, whereas tool overhang interacts with feed rate. The best result of surface roughness was obtained using low or medium values of overhang with low speed and /or feed rate. Minimum maximum tensile residual stress can be obtained with a combination of tool overhang of 37 mm with very low depth of cut, low rotational speed and feed rate of 0.188 mm/rev.


2012 ◽  
Vol 527 ◽  
pp. 167-172 ◽  
Author(s):  
Oskars Linins ◽  
Juris Krizbergs ◽  
Irina Boiko

The aim of this work is to propose a methodology of lifetime prediction of details by new approach for linear wear intensity determination using 3D surface roughness parameters. For qualitative evaluation of the wear process the linear wear intensity (Ih), which may be determined separately for the plastic and elastic contact, is commonly used. Since the elastic contact is mainly required in pairs of details in mechanical engineering in these paper this kind of contact was examined. In our research, the random surface model was used. The surface machined with abrasive instruments (grinding, polishing, honing, etc) has the irregular shape of surface roughness, which can be described with random function. Irregular surface is expressed by a random field h(x, y) of two variables x and y which are Cartesian coordinates of a surfaces point, where the height of roughness asperity h(x, y) has a normal probability distribution. In wear research the probability theory was used. Further in deformed volume calculation, as well as in determination of the length of the surface’s contact the 3D surface roughness parameters were used. The strong correlation between 3D roughness parameters Sa (arithmetic mean height) and Str=Rsm1/Rsm2 (texture aspect ratio of the surface) was revealed. As a result of research, the methodology of lifetime prediction of details by new approach for linear wear intensity determination using 3D surface roughness parameters was elaborated and proposed. After calculation of linear wear intensity Ih, it is possible to estimate lifetime of wearing details. So, at a first time in wear estimation the 3D surface roughness parameters were used. The results of this work have wide practical application, for example in design, texture specification on drawings etc.


2018 ◽  
Vol 919 ◽  
pp. 92-100
Author(s):  
Peter Košťál ◽  
Jana Moravčíková ◽  
Daynier Rolando Delgado Sobrino ◽  
Radovan Holubek

In order to increase the cutting and breaking capacity of abrasive water jet machining (AWJM), abrasive particles are usually added to water. The AWJM technology is generally used for harder and heavier machinable materials like thick sheets, composite materials with metal and ceramic properties and others within these categories to just cite a few. The contribution is mainly focused on the analysis of the surface properties of the steel S235 after the cutting process, and this depending on the cutting speed of the water jet. Three different cutting speeds were used for the analysis because this cutting parameter significantly affects the resulting quality of the machined surface. A contact profile method was used to analyze surface roughness. The observed surface roughness parameters were the Ra, Rt and Rz respectively. The above-mentioned surface roughness parameters were measured in three positions, i.e.: at the inlet, middle and exit positions of the water jet with respect to the machined material.


2016 ◽  
Vol 721 ◽  
pp. 373-377
Author(s):  
Armands Leitans ◽  
Oskars Linins ◽  
Irina Boiko

This work is devoted to the elaboration of the new methodology for the wear parts contact estimation using 3D surface roughness parameters defined in the standard ISO 25178-2:2012 for friction and wear rate determination. In our research the random surface model was used, where the height of surface asperities h (x,y) has a normal probability distribution. As a result of research the equations for estimation of the elastic contact area and friction coefficient were derived. The existence of the correlation between friction coefficient and 3D surface roughness parameters was proven as well. The results of this work could have wide practical application, for example in design, for the texture specification on drawings, calculation of load, etc.


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