scholarly journals Cutting Forces and Tool Wear Investigation during Turning of Sintered Nickel-Cobalt Alloy with CBN Tools

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1623
Author(s):  
Wojciech Zębala ◽  
Grzegorz Struzikiewicz ◽  
Ksenia Rumian

This article describes issues related to the machining of parts made of sintered nickel-cobalt alloy. Longitudinal turning with a CBN (cubic boron nitride) tool was analyzed. The results of experiments showed the influence of cutting parameters in the field of finishing machining on the values of cutting forces and specific cutting force, taking into account the wear of the cutting edge. Measurements and analysis of the topography and roughness parameters of the machined surface, as well as the cutting tool wear, were presented. The microscopic examination showed that the average grain size of the sintered nickel-cobalt alloy was 3.22 ± 0.1 (μm). The presence of the hardening state variability of the material during machining, as well as the value of the cutting force fluctuation as a function of the tool wear VB, were stated. The specific cutting force values increased to a small degree for the tool wear in the range of VB = 0–0.2 mm, and reached similar values in the range kc = 5500–7500 N/mm2. The specific cutting force values increased significantly for wear VB > 0.2 mm and were characterized by a large variability. The occurring phenomena were analyzed and several explanations were proposed. A recommendation was developed for the machining of parts made of sintered nickel-cobalt alloy. The Taguchi method was used in the experiment methodology.

2021 ◽  
Vol 2021 (4) ◽  
pp. 4836-4840
Author(s):  
ROBERT STRAKA ◽  
◽  
JOZEF PETERKA ◽  
TOMAS VOPAT ◽  
◽  
...  

The article compares two cutting edge preparation methods and their influence on the machined surface roughness of the difficult to cut nickel alloy Inconel 718 and the tool wear of cutting inserts made of cemented carbide. The manufacturing and preparation process of cutting inserts used in the experiment were made by Dormer Pramet. The preparation methods used in the experiment were drag finishing and brushing. Cutting parameters did not change during the whole turning process to maintain the same conditions in each step of the process and were determined based on tests for a semi-finishing operation of the turning process. To obtain durability of 25 to 30 minutes with controlled development of the tool wear the cutting parameters were determined with cooperation with the cutting inserts manufacturer.


2018 ◽  
Vol 5 ◽  
pp. 12
Author(s):  
Yanfeng Gao ◽  
Yongbo Wu ◽  
Jianhua Xiao ◽  
Dong Lu

Titanium alloys are extensively applied in the aircraft manufacturing due to their excellent mechanical and physical properties. At present, the α + β alloy Ti6Al4V is the most commonly used titanium alloy in the industry. However, the highest temperature that it can be used only up to 300 °C. BTi-6431S is one of the latest developed high temperature titanium alloys, which belongs to the near-α alloy group and has considerably high tensile strength at 650 °C. This paper investigates the machinability of BTi-6431S in the terms of cutting forces, chip formation and tool wear. The experiments are carried out in a range of cutting parameters and the results had been investigated and analyzed. The investigation shows that: (1) the specific cutting forces in the machining of BTi-6431S alloy are higher than in the machining of Ti6Al4V alloy; (2) the regular saw-tooth chips more easily formed and the shear bands are narrower in the machining of BTi-6431S; (3) SEM and EDS observations of the worn tools indicate that more cobalt elements diffuse into the workpiece from tool inserts during machining of BTi-6431S alloy, which significantly aggravates tool wear rate. The experimental results indicate that the machinability of BTi-6431S near alpha titanium alloy is significantly lower than Ti-6Al-4V alloy.


Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1338
Author(s):  
Lakshmanan Selvam ◽  
Pradeep Kumar Murugesan ◽  
Dhananchezian Mani ◽  
Yuvaraj Natarajan

Over the past decade, the focus of the metal cutting industry has been on the improvement of tool life for achieving higher productivity and better finish. Researchers are attempting to reduce tool failure in several ways such as modified coating characteristics of a cutting tool, conventional coolant, cryogenic coolant, and cryogenic treated insert. In this study, a single layer coating was made on cutting carbide inserts with newly determined thickness. Coating thickness, presence of coating materials, and coated insert hardness were observed. This investigation also dealt with the effect of machining parameters on the cutting force, surface finish, and tool wear when turning Ti-6Al-4V alloy without coating and Physical Vapor Deposition (PVD)-AlCrN coated carbide cutting inserts under cryogenic conditions. The experimental results showed that AlCrN-based coated tools with cryogenic conditions developed reduced tool wear and surface roughness on the machined surface, and cutting force reductions were observed when a comparison was made with the uncoated carbide insert. The best optimal parameters of a cutting speed (Vc) of 215 m/min, feed rate (f) of 0.102 mm/rev, and depth of cut (doc) of 0.5 mm are recommended for turning titanium alloy using the multi-response TOPSIS technique.


Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1014 ◽  
Author(s):  
Sánchez Hernández ◽  
Trujillo Vilches ◽  
Bermudo Gamboa ◽  
Sevilla Hurtado

In this work, the analysis of the cutting speed and feed rate influence on tool wear and cutting forces in Ti6Al4V alloy dry machining is presented. The study has been focused on the machining in a transient state. The tool wear mechanisms, tool wear intensity and cutting forces evolution have been analyzed as a function of the cutting parameters. Experimental results show that the main cutting force amplitude exhibits a general trend to increase with both cutting parameters. Crater wear was more evident at high cutting speeds, whereas flank wear was present on the whole interval of the cutting parameters analyzed. Furthermore, the cutting speed shows a slightly higher influence on crater wear and the feed rate shows a higher influence on flank wear. Finally, several experimental parametric models have been obtained. These models allow predicting the evolution of crater and flank tool wear, as well as the cutting forces, as a function of the cutting parameters. Additionally, a model that allows monitoring the tool wear on the machining transient state as a function of the main cutting force amplitude has been developed.


Author(s):  
Tao Chen ◽  
Weijie Gao ◽  
Guangyue Wang ◽  
Xianli Liu

Torus cutters are increasingly used in machining high-hardness materials because of high processing efficiency. However, due to the large hardness variation in assembled hardened steel workpiece, the tool wear occurs easily in machining process. This severely affects the machined surface quality. Here, we conduct a research on the tool wear and the machined surface quality in milling assembled hardened steel mold with a torus cutter. The experimental results show the abrasive wear mechanism dominates the initial tool wear stage of the torus cutter. As the tool wear intensifies, the adhesive wear gradually occurs due to the effect of alternating stress and impact load. Thus, the mixing effect of the abrasive and adhesive wears further accelerates tool wear, resulting in occurrence of obvious crater wear band on the rake face and coating tearing area on the flank face. Finally, the cutter is damaged by the fatigue wear mechanism, reducing seriously the cutting performance. With increase of flank wear, moreover, there are increasingly obvious differences in both the surface morphology and the cutting force at the two sides of the joint seam of the assembled hardened steel parts, including larger height difference at the two sides of the joint seam and sudden change of cutting force, as a result, leading to decreasing cutting stability and deteriorating seriously machined surface quality.


Fractals ◽  
2019 ◽  
Vol 27 (02) ◽  
pp. 1950013 ◽  
Author(s):  
AHMAD THUFFAIL THASTHAKEER ◽  
ALI AKHAVAN FARID ◽  
CHANG TECK SENG ◽  
HAMIDREZA NAMAZI

Analysis of the machined surface is one of the major issues in machining operations. On the other hand, investigating about the variations of cutting forces in machining operation has great importance. Since variations of cutting forces affect the surface quality of machined workpiece, therefore, analysis of the correlation between cutting forces and surface roughness of machined workpiece is very important. In this paper, we employ fractal analysis in order to investigate about the complex structure of cutting forces and relate them to the surface quality of machined workpiece. The experiments have been conducted in different conditions that were selected based on cutting depths, type of cutting tool (serrated versus. square end mills) and machining conditions (wet and dry machining). The result of analysis showed that among all comparisons, we could only see the correlation between complex structure of cutting force and the surface roughness of machined workpiece in case of using serrated end mill in wet machining condition. The employed methodology in this research can be widely applied to other types of machining operations to analyze the effect of variations of different parameters on variability of cutting forces and surface roughness of machined workpiece and then investigate about their correlation.


2009 ◽  
Vol 69-70 ◽  
pp. 413-417
Author(s):  
Z.H. Wang ◽  
Jun Tan Yuan ◽  
X.Q. Hu ◽  
X.W. Xiong

Cutting force is a key factor influencing the machining deformation of weak rigidity workpieces. In order to reduce the machining deformation and improve the process precision and the surface quality, it is necessary to study the factors influencing the cutting force and build the regression model of cutting forces. Firstly, the cutting parameters influencing cutting force are analyzed for LF21. Secondly, how certain cutting parameter influence the cutting component forces (Fx, Fy, Fz) are studied by the correlation analysis and the approach to choosing the right cutting parameters for machining the weak rigidity workpieces are presented. Finally, the regression model of cutting forces based on the cutting parameters is investigated in this paper.


2012 ◽  
Vol 723 ◽  
pp. 365-370 ◽  
Author(s):  
Rong Bian ◽  
Eleonora Ferraris ◽  
Jun Qian ◽  
Dominiek Reynaerts ◽  
Liang Li ◽  
...  

This work presents an experimental investigation on micro-milling of fully sintered Zirconia (ZrO2) by diamond coated tools. The experiments were conducted on a Kern MMP 2522 micro-milling centre and WC micro end mills, diamond coated by chemical vapour deposition (CVD) and of stiff geometry were employed as cutting tools. The effects of cutting parameters and milling time on tool wear were investigated. The results revealed that the tool wear characters included diamond coating delamination and wear of substrate WC. Both cutting forces and machined surface quality were affected by tool wear with the progress of milling.


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