A Model for the Contact Conditions at the Chip-Tool Interface in Machining

2003 ◽  
Vol 125 (3) ◽  
pp. 649-660 ◽  
Author(s):  
B. Ackroyd ◽  
S. Chandrasekar ◽  
W. D. Compton

A high-speed photographic study has been made of the chip-tool interface and its evolution when cutting pure metals with optically transparent sapphire tools. The use of a high speed camera in conjunction with an optical microscope has enabled details of the interface, including the velocity field along the interface, to be resolved at high spatial and temporal resolution while cutting at speeds between 1 mm/sec and 2000 mm/sec. The results show the chip-tool contact along this interface to be composed of four distinct regions: a region of stagnation at the cutting edge, a region of retardation adjoining the stagnation region, a region of sliding beyond the retardation region, followed by a region of metal transfer or “sticking” that is located furthest away from the cutting edge alongside the boundary of the contact. The chip and tool appear to be in intimate contact over the stagnation, retardation, and sliding regions, with sliding occurring at the interface over much of this zone of intimate contact. These observations have provided direct experimental evidence for a model of the contact conditions proposed by Enahoro and Oxley based on analytical considerations. Cutting experiments with non-oxide tools such as aluminum and high speed steel suggest that this description conditions is equally applicable to tool materials other than sapphire.

2012 ◽  
Vol 538-541 ◽  
pp. 1299-1303
Author(s):  
Ze Ping Fang ◽  
Xi Bin Wang ◽  
Zhi Bing Liu

Considering the tribological characteristics of the micro-cutting, an approach that divided the micro-cutting area into four parts based on the contact stress and speed was proposed to the friction performance research. Friction tests under different conditions were carried out on a UMT3 tribometer and a special tribometer assembled based on HAWK TC-150 turning lathe. The morphological analyses of the worn surface were made by optical microscope and scanning electron microscope. The experimental results indicated that different rubbing pairs had different friction properties under different speeds or loads; for stainless steel, high speed steel showed a better friction performance in low speed and load, while cemented carbide has more advantages in high speed or high load. Hence, a suitable choice principle was proposed for the micro-cutting tool material based on the tribological characteristic.


2016 ◽  
Vol 693 ◽  
pp. 1585-1590
Author(s):  
Yi Zhuo Guo ◽  
Xian Guo Yan ◽  
Shu Juan Li ◽  
Hong Guo

Many studies have proved the service life of cutter can be prolonged by electrolytic strengthening. Based on the theory of electrolytic strengthening technology, this paper introduced and developed prototype equipment for strengthening cutting edge of rotary cutter and put forward a calculation method of total electric quantity consumption during the electrolysis suitable for microcontroller. The M8 high-speed steel tap is taken as a strengthening example. After finished the strengthening process that it clearly see the results of the surface of tap was obviously polished by observing the micrograph. This equipment improves the reliability of electrolytic strengthening and the cost is relatively cheap.


2000 ◽  
Author(s):  
Paul A. Clayton ◽  
Mohamed A. Elbestawi ◽  
Tahany El-Wardany ◽  
Dan Viens

Abstract This paper presents a five-axis milling force model that can incorporate a variety of cutters and workpiece materials. The mechanistic model uses a discretized cutting edge to calculate an area of intersection which is multiplied by the specific cutting pressure to produce a force output along the primary cartesian coordinate system. By using an analytic description of the cutting edge with a non-specific cutter and workpiece intersection routine, a model was created that can describe a variety of cutting situations. Furthermore, a back propagation neural network is used to calibrate the model, providing robustness and scalability to the calibration process. Testing was performed on 1020 steel using various cutting parameters with a high speed steel two flute cutter and a tungsten carbide insert cutter. Furthermore, both linear cuts and a test die surface yielded good agreement between predicted and measured results.


2019 ◽  
Vol 130 ◽  
pp. 01031 ◽  
Author(s):  
The Jaya Suteja ◽  
Yon Haryono ◽  
Andri Harianto ◽  
Esti Rinawiyanti

Polyacetal is commonly used as bushing material because of its low coefficient of friction and self lubricant characteristics. The polyacetal is machined by using boring process to produce bushing in certain surface roughness. The objectives of this research are to optimize three independent parameters (depth of cut, feed rate and principal cutting edge angle) of boring process of polyacetal using high speed steel tool to achieve the highest material removal rate and the required surface roughness. Response Surface Methodology is used to investigate the influence of the parameters and optimize the boring process. The research shows that the influence of the boring process parameters on polyacetal is similar compared to on metal. The result reveals that the optimum result is achieved by applying the value of depth of cut, feed rate, and principal cutting edge angle is 2.9 × 10–3 m, 0.229 mm rev–1, and 99.1° respectively. By applying these values, the maximum material rate removal achieved in this research is 1263.4 mm3 s–1 and the surface roughness achieved is 1.57 × 10–6 m.


1993 ◽  
Vol 308 ◽  
Author(s):  
Ru Wang

ABSTRACTThe validity of Lc of film failure is studied with friction — detected scratch test . The specimens used in the experiment are ion-plated TiN and Ti films,Chemical-Plated NiPCu films on steel of various hardness,ion beam mixed plated TiN films on optical glass,The morphology of failed films was studied under optical microscope and scanning electronmicroscope,The composition of starting failure of films was analyzed with electro — probe. It is found that in the curves of scratch tests of ion-plated TiN and Ti films on high-speed steel,the load corresponding the sudden change of the horizontal force is the same as the critical load of film failure,however,the critical load obtained in the scratch test of the ion-plated TiN and Ti films on soft steel is the some deference compared with optical microscope analyzed, that is principally due to the property of films and substrates (hardness and coefficient).The morphology and mechanism of ion — plated TiN and Ti films on high —speed steel are also studied in the paper.The adhesion between film and substrate is an effective method in evaluating the films property. After apprasing the effectiveness of acoustic emission monitoring scratch test, someone think that no matter coated with hard or soft film it is effective on the brittle hard substrate. However,there exist errors to different extent on other film-substrate system,and the scratch test is inapplicable for soft film-soft substrate system[1]. P. A. Steinmann pointed out while studying the factors influnceing the critical load Lc,that friction coefficient is a key factor on Lc,it provided valuable information in measuring Lc,but it think it is imporsible to measure Lc totally dependent on sudden change friction or friction coefficient, howeveer, for a specific coating substrate system,it is acceptable to say that Lc is dependent on friction coefficient[2]. This paper study experimentally on the friction detected scratch test and found out that effectiveness of Lc varies substantially in different film-substrate system. The author studiied the regularity of various system and discuse the season. The failure morphology and principles of ion-plated TiN and Ti film on highspeed steel are also analyzed in this paper.


2009 ◽  
Vol 69-70 ◽  
pp. 515-519 ◽  
Author(s):  
Yun Xian Cui ◽  
Bao Yuan Sun ◽  
W.Y. Ding ◽  
F.D. Sun

In the paper, a new multilayer composition thin film thermocouple was developed, which can accurately measure the temperature nearby cutting edge in convenient and fast ways. By means of advanced Twinned microwave ECR plasma source enhanced Radio Frequency (RF) reaction non-balance magnetron sputtering technique, SiO2 insulating film, NiCr/NiSi sensor film and SiO2 protecting film were deposited on the surface HSS substrate. Both static calibration and dynamic calibration were completed. The results showed that the sensor had good performance, good linearity, quick dynamic response, response time constant was 12.7ms. The temperature near the cutting edge in cutting process of aluminum alloy was measured by the developed sensor. The bonding strength between multiple layer film and substrate of high-speed-steel met the presupposed demands.


2020 ◽  
Vol 62 (3) ◽  
pp. 265-270
Author(s):  
Zainul Huda ◽  
Muhammad Hani Ajani ◽  
Muhammad Saad Ahmed

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