Wear Performance Evaluation of Tungsten Carbide Taps in Blind Hole Tapping Cast Iron

2010 ◽  
Vol 126-128 ◽  
pp. 755-759 ◽  
Author(s):  
Ming Chen ◽  
Xiao Hui Zhang ◽  
Bing Han ◽  
Bin Rong ◽  
Gang Liu

The engineblock and cylinderhead of automobile are usually made of cast iron, and tapping of blind holes is one of the most demanding operations. As usual, tapping is the final process for an engineblock, and the failure of taps can disable the engineblock possibly. The productivity is restricted because of the low cutting speed and poor wear resistance of high speed steel (HSS) taps. Thereby, according to the demand on high speed cutting and low tact time of modern engine production lines, several new typical special tungsten carbide taps are developed and their cutting performance are evaluated in comparison with the commercial taps. In the process of tapping blind holes in gray cast iron and ductile cast iron, several aspects are studied comparatively such as wear mechanism of the first complete and the last incomplete tooth, tap structure, wear of TiCN coating and effects of coolant on cutting performance of taps. This study indicates that straight coated taps with fewer flutes are suitable for high speed tapping of cast iron.

2010 ◽  
Vol 29-32 ◽  
pp. 1527-1531
Author(s):  
Fa Zhan Yang ◽  
Jian Qiang Zhou ◽  
Guang Yao Meng ◽  
Jun Zhao ◽  
Chang He Li

Wear behavior of WC based nanocomposite cutting tool when high speed cutting ductile cast iron was investigated. Orthogonal cutting tests were carried out on a CA6140 lathe using three speeds, namely, 100, 215 and 287m min-1. The WC based nanocomposite tool is found to be superior to cemented carbide tools (YG8). The tool life is prolonged 60% as compared to cemented carbide, as the width of the wear land (VB), which was monitored at selected time intervals. Meanwhile, the topography of worn surfaces was scanned by a profilemeter. Wear characterization of the rake face and the flank surfaces as well as of the collected chips was conducted using a scanning electron microscopy (SEM). Results showed that distinctive traces of single abrasive tool wear event were found on the rake face of the tool, additionally, the adhesion wear is the main wear mechanism in the flank face of the tool. However, the extent of improvement in tool life depends strongly on the cutting conditions, with the greatest benefits being seen at higher cutting speeds and feed rates.


2014 ◽  
Vol 657 ◽  
pp. 88-92
Author(s):  
Traian Grămescu ◽  
Constantin Cărăușu

In the laboratory of cutting machining technologies from the “Gheorghe Asachi” Technical University of Iaşi, a series of investigations on the machinability of cast iron samples having various structures were designed and developed. The aim of the research was to know and to explain the way in which various constituents of some iron castings exert influence on the degree of wear of a milling tool made of high speed steel. Within this research, mathematical empirical models were determined, in order to calculate the cutting speed v60, considered as an indicator for the evaluation of machinability. The research allowed establishing the factors able to have a major influence on tool wear phenomenon and obtaining thus a more complete image concerning the machinability of grey iron used for castings.


2014 ◽  
Vol 8 (4) ◽  
pp. 550-560 ◽  
Author(s):  
Naoki Takahashi ◽  
◽  
Jun Shinozuka

This study investigates the contributions of high-speed cutting and a high rake angle to the improvement of the cutting performance of natural rubber. Orthogonal cutting experiments were conducted at cutting speeds ranging from 1.0 m/s to 141.1 m/s. The rake angles examined were 0°, 20° and 50°. The following results were obtained from the experiments. The cutting ratio is almost 1.0 regardless of the cutting speed and rake angle. The cutting force rises rapidly as the cutting speed increases. High-speed cutting or a high rake angle eliminates tear defects on the machined surface and reduces chipping defects at the entry edge of the workpiece. An uncut portion, however, always remains at the exit edge. The cross-sectional shape of the machined surface becomes concave. Besides, the machined surface comes into broad contact with the clearance face. These degradations in the shape accuracy arise from the large elastic distortion that occurs in the shear zone. Increasing the cutting speed improves the flatness of the machined surface. Although an analysis of the cutting mechanism reveals that the apparent stiffness of the material in the shear zone is enhanced with increasing the cutting speed, a very high cutting speed worsens the shape accuracy because of the development of shock waves. Depending on the rake angle, there is a critical cutting speed that should not be exceeded to maximize the cutting performance of natural rubber.


2013 ◽  
Vol 589-590 ◽  
pp. 390-394
Author(s):  
Hai Dong Yang ◽  
Ju Li Hu ◽  
Yu Ming Zou ◽  
Xiao Yang ◽  
Xiao Jun Liu

Through the experiment of cutting 45 steel, the influence of boronizing on Ti (C,N)-based ceramic cutting performance in different cutting speeds were discussed. The test results indicated that: regardless of boriding, cutting speed has a great influence on the life of Ti (C,N)-based ceramic cutting tool. Within the limit of 200~400 m/min, the lower the cutting speed is, the longer tools life. At the minimum speed, boronizing greatly improves cutting performance and doubles tool life. It has no significant but negative effects once over 300 m/min. The decrease of the abrasion resistance of boronized layer is mainly influenced by the intense thermal shock of high speed cutting.


Metals ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 390 ◽  
Author(s):  
Yulong Cao ◽  
Zhouhua Jiang ◽  
Yanwu Dong ◽  
Xin Deng ◽  
Lev Medovar ◽  
...  

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Fritz Klocke ◽  
Kristian Arntz ◽  
Gustavo Francisco Cabral ◽  
Martin Stolorz ◽  
Marc Busch

In this experimental study, the cutting performance of ball-end mills in high-speed dry-hard milling of powder metallurgical steels was investigated. The cutting performance of the milling tools was mainly evaluated in terms of cutting length, tool wear, and cutting forces. Two different types of hardened steels were machined, the cold working steel HS 4-2-4 PM (K490 Microclean/66 HRC) and the high speed steel HS 6-5-3 PM (S790 Microclean/64 HRC). The milling tests were performed at effective cutting speeds of 225, 300, and 400 m/min with a four fluted solid carbide ball-end mill ( = 6, TiAlN coating). It was observed that by means of analytically optimised chipping parameters and increased cutting speed, the tool life can be drastically enhanced. Further, in machining the harder material HS 4-2-4 PM, the tool life is up to three times in regard to the less harder material HS 6-5-3 PM. Thus, it can be assumed that not only the hardness of the material to be machined plays a vital role for the high-speed dry-hard cutting performance, but also the microstructure and thermal characteristics of the investigated powder metallurgical steels in their hardened state.


2012 ◽  
Vol 426 ◽  
pp. 168-171
Author(s):  
L.J. Ma ◽  
Y. D. Gong

Though the high-speed cutting experimentation of high alloy antifriction cast iron, the materials performance and request on tools in cutting were analyzed. Though single-factor experimentation, the factors of affecting on cutting efficiency were discussed, such as tools materals, cutting speed, feed speed and cutting depth. The results show that the durability of PCBN tools is higher, but the durability of ceramics and tungsten-cobalt carbide tipped tools is low. The influence curve of cutting speed to machining efficiency is a part of parabola. And the influence curve of cutting depth to machining efficiency can be divided two parts of materials removal and tools wear. In the ensuring of technical requirements of work-piece machining. The high cutting efficiency can be obtained, when cutting speed vc=75~100m/min, feed speed f≤8mm and cutting depth ap =0.1~0.3mm.


2019 ◽  
Vol 13 (3) ◽  
pp. 213-217
Author(s):  
Sanja Šolić ◽  
Zdravko Schauperl ◽  
Vlado Tropša

High speed steel (HSS) is a very important industrial tool material and has been constantly improved for different wear resistance applications and cutting tools, i.e. drills, milling cutters, hobs and for the cutting tools in which the economical cutting speed is too low for choosing the carbide tools. The properties of HSS depend significantly on the parameters of the conducted heat treatment. In this paper, the influence of deep cryogenic treatment in combination with nitriding of metallurgical powder metallurgy HSS on the wear resistance was measured. Additionally, the cutting performance in a single point cutting tool machinability test at the configuration of the dry low-speed turning of steel was investigated. The results showed that deep cryogenic treatment itself, and in combination with nitriding, resulted in the reduction of the wear rate. The results of the single point cutting tool machinability test showed that deep cryogenic treated and nitrided HSS inserts performed worse than the classically heat-treated inserts and deep cryogenic treated HSS inserts exhibited approximately the same flank wear as the nitrided ones.


2014 ◽  
Vol 1077 ◽  
pp. 56-60 ◽  
Author(s):  
Akio Kubo ◽  
Hua Qiu ◽  
Hironori Matsuoka

This paper presents the results of a systematic dry hobbing experiment performed on a general mechanical transmission type of hobbing machine. All four types of coated HSS hobs demonstrate satisfactory cutting performance applicable enough to practical production. Some related details such as the characteristics of hob wear, the effect of chip crush behavior and cutting speed are also discussed based on the experiment results.


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