scholarly journals Experimental Verification of Chatter-Free Ball End Milling Strategy

2013 ◽  
Vol 7 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Lin Lu ◽  
◽  
Masahiko Sato ◽  
Hisataka Tanaka ◽  

Chatter vibration frequently occurs in ball end milling. If the characteristics of the cutting tool system and cutting process are known, chatter stability in ball end milling can be evaluated. Hence, in this paper, a chatter-avoidance strategy based on a regenerative chatter theory is proposed to prevent the occurrence of chatter. This consists of a simulation of chatter stability and cutting condition control. When the characteristics of a vibration system change, this chatter-avoidance strategy cannot cope with it. Therefore, another chatter-avoidance control algorism that changes cutting parameters on a machining center is proposed. This can adapt to the change in the characteristics of the vibration systemduring cutting. The effectiveness of the two chatter-avoidance methods proposed is examined through experiments.

2011 ◽  
Vol 291-294 ◽  
pp. 3013-3023 ◽  
Author(s):  
Somkiat Tangjitsitcharoen ◽  
Channarong Rungruang

In order to realize the environmental hazard, this paper presents the investigation of the machinability of ball-end milling process with the dry cutting, the wet cutting, and the mist cutting for aluminum. The relations of the surface roughness, the cutting force, and the cutting parameters are examined based on the experimental results by using the Response Surface Analysis with the Box-Behnken design. The in-process cutting force is monitored to analyze the relations of the surface roughness and the cutting parameters. The proper cutting condition can be determined easily referring to the minimum use of cutting fluid, and the minimum surface roughness and cutting force of the surface plot. The effectiveness of the obtained surface roughness and cutting force models have been proved by utilizing the analysis of variance at 95% confident level.


2011 ◽  
Vol 223 ◽  
pp. 554-563 ◽  
Author(s):  
Noemia Gomes de Mattos de Mesquita ◽  
José Eduardo Ferreira de Oliveira ◽  
Arimatea Quaresma Ferraz

Stops to exchange cutting tool, to set up again the tool in a turning operation with CNC or to measure the workpiece dimensions have direct influence on production. The premature removal of the cutting tool results in high cost of machining, since the parcel relating to the cost of the cutting tool increases. On the other hand the late exchange of cutting tool also increases the cost of production because getting parts out of the preset tolerances may require rework for its use, when it does not cause bigger problems such as breaking of cutting tools or the loss of the part. Therefore, the right time to exchange the tool should be well defined when wanted to minimize production costs. When the flank wear is the limiting tool life, the time predetermination that a cutting tool must be used for the machining occurs within the limits of tolerance can be done without difficulty. This paper aims to show how the life of the cutting tool can be calculated taking into account the cutting parameters (cutting speed, feed and depth of cut), workpiece material, power of the machine, the dimensional tolerance of the part, the finishing surface, the geometry of the cutting tool and operating conditions of the machine tool, once known the parameters of Taylor algebraic structure. These parameters were raised for the ABNT 1038 steel machined with cutting tools of hard metal.


2014 ◽  
Vol 939 ◽  
pp. 201-208
Author(s):  
Kosuke Hattori ◽  
Hiroyuki Kodama ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama

Chatter vibration in cutting processes usually leads to surface finish degradation, tool damage, cutting noise, energy loss, etc. Self-excited vibration particularly seems to be a problem that is easily increased to large vibration. The regenerative effect is considered as one of the causes of chatter vibration. Although the chatter vibration occurs in various types of processing, the end-milling is a typical process that seems to cause the chatter vibration due to a lack of rigidity of one or more parts of the machine tools, cutting tool, and work-piece. The aim of our research is to propose a simple method to control chatter vibration of the end-milling process on the basis of a coupling model integrating the related various elements. In this study, hammering tests were carried out to measure the transfer function of a machine tool and cutting tool system, which seems to cause vibration. By comparing these results, finite elemental method (FEM) analysis models were constructed. Additionally, cutting experiments were carried out to confirm the chatter vibration frequencies in end-milling with a machining center. In the hammering tests, impulse hammer and multiple acceleration pick-ups are connected to a multi-channel FFT analyzer and estimate the natural frequencies and natural vibration modes. A simplified FEM model is proposed by circular section stepped beam elements on the basis of the hammering test results, considering a coupling effect. In comparisons of the calculated results and hammering test results, the vibration modes are in good agreement. As a result, the proposed model accurately predicts the chatter vibration considering several effects among the relating elements in end-milling. Moreover, it can be seen that the chatter vibration is investigated from a viewpoint of the integrating model of the end-milling process.


2014 ◽  
Vol 13 (01) ◽  
pp. 41-54 ◽  
Author(s):  
S. Kalidass ◽  
P. Palanisamy

Tool wear of a cutting tool has a significant impact on the tool life and surface quality of the finished product. Tool wear is influenced by many factors such as cutting parameters, tool geometry, coating type, work piece material, chatter, and cutting condition. In the present work, the design of experiments (DOE) technique has been used for four factors at five levels to conduct experiments. Tool wear is taken as the response variable measured during end milling, while helix angle, spindle speed, feed and depth of cut are taken as the input parameters. The material and tool selected for this study are AISI 304 stainless steel and uncoated solid carbide end mill cutter respectively. The tool wear was measured using tool maker's microscope. The experimental values are used in six sigma software for finding the coefficients to develop the regression model. The direct and interaction effect of the machining parameter with tool wear were analyzed using contour graphs, which helped to select process parameters for reducing tool wear and also ensure quality of milling.


2020 ◽  
Vol 14 (1) ◽  
pp. 18-25
Author(s):  
Haruhiko Suwa ◽  
Soushi Sakamoto ◽  
Masafumi Nagata ◽  
Kazuhiro Tezuka ◽  
Tetsuo Samukawa ◽  
...  

Sintered tungsten carbide which has high hardness and high heat resistance, has been widely used in molds and dies. Research on the development of a cutting technology for sintered tungsten carbide (sintered WC-Co alloy) has been pursued mainly with the use of a turning process. We focused on building an efficient milling method for sintered tungsten carbide by using diamond-coated ball end tools, and have investigated their basic properties under specific cutting conditions. This study extends our previous work by enhancing cutting distance in the milling of sintered tungsten carbide, especially that with a “fine” WC grain. The surface roughness of cut workpieces is evaluated from the point of view of the quality of surface roughness. A series of cutting experiments under different cutting conditions were carried out, and the possibility of deriving a suitable cutting condition for the ball end milling of sintered tungsten carbide is discussed.


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