scholarly journals Study of the Effects of Initial Cutting Conditions and Transition Period on Ultimate Tool Life when Machining Inconel 718

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 592
Author(s):  
Morvarid Memarianpour ◽  
Seyed Ali Niknam ◽  
Sylvain Turenne ◽  
Marek Balazinski

Rapid tool wear and limited tool life are major problems when machining Inconel 718, which still need further attention. Amongst the reported strategies, limited studies have been reported on optimizing initial cutting conditions by means of tool life improvement. Therefore, in this work, the tool wear progress and tool life were investigated by varying the initial conditions in the transition period, which was set at four seconds. The transition point was discovered by previous works by the authors. After the transition point, similar cutting conditions were used as the reference condition. The tool wear morphology and size were recorded and analyzed in each condition. It was revealed that applying a lower cutting speed and feed rate in the transition period led to improved tool life as compared to the reference condition. In other words, the use of optimum levels of cutting parameters in the transition period of the cutting process may enhance tool life at higher cutting time. For instance, initial feed rate (0.15 mm/rev) and cutting speed (25 m/min) led to the improvement in the ultimate tool life by about 67% and 50%, respectively. Besides, applying the lower initial cutting speed, i.e., 25 m/min, increased the tool life by about 50% when the insert reached the maximum flank wear (vBmax) of 300 µm in comparison with those at higher initial cutting speeds. This phenomenon may lead to better insight into the effect of the influence of the initial cutting conditions in the transition period on tool life when machining hard-to-cut materials. Moreover, the built-up edge (BUE) was exhibited as the primary wear mode in all cutting conditions.

2014 ◽  
Vol 564 ◽  
pp. 566-571
Author(s):  
K. Kamdani ◽  
Sulaiman Hasan ◽  
Mohd Amri Lajis

Inconel 718 is a registered trademark of Special Metals Corporation that refers to a family of austenitic nickel-chromium-based super alloys. This material usually being used or operate in high temperature and extreme condition like aerospace industry, turbocharger rotors and seals. This research presents an experimental study of the cutting force variation, surface roughness, tool life and tool wear in end milling Inconel 718. The experimental results showed that flank wear was the predominant failure mode affecting tool life for TiAlN and TiN coated carbide tool. TiAlN is the better coated tool than TiN because it produce better surface finish and resultant force. Feed rate is one of the parameter that effecting results in this experiment. The higher feed rate will shorten the life of the tool. Although for the cutting condition, the situation is quite different where the proper cutting speed will maintain the tool life and tool wear for cutting tool. The overall study shows that TiAlN coated carbide tool with cutting speed 100 m/min, depth of cut 0.5 mm and feed rate 0.1 mm/tooth is the optimum parameter in this experiment.


2010 ◽  
Vol 26-28 ◽  
pp. 1052-1055
Author(s):  
Li Fa Han ◽  
Sheng Guan Qu

The wear characteristics and life of Al2O3/(W,Ti)C ceramic tool in turning NbCp-reinforced iron-based P/M composites was investigated. Experimental results indicate that cutting parameters have an influence on tool wear, among which cutting speed and depth of cut seem to be more prominent. The maximum flank wear rapidly increases as the increase in cutting speed and depth of cut. While, it increases gradually as the decrease in feed rate. Meanwhile, an empirical model of tool life is established, from which the influence of cutting speed and depth of cut on tool life is far greater than that of feed rate. Also from the empirical model, the preferable range of cutting parameters was obtained.


Author(s):  
Xuan-Truong Duong ◽  
Marek Balazinski ◽  
René Mayer

The initial tool wear during machining of titanium metal matrix composite (TiMMCs) is the result of several wear mechanisms: tool layer damage, friction - tribological wear, adhesion, diffusion and brace wear. This phenomenon occurs at the first instant and extends to only ten seconds at most. In this case the adhesive wear is the most important mechanism while the brace wear is considered as a resistance wear layer at the beginning of the steady wear period. In this paper, the effect of the initial tool wear and initial cutting conditions on tool wear progression and tool life is investigated. We proposed herein a new mathematical model based on the scatter wear and Lyapunov exponent to study quantitatively the “chaotic tool wear”. The Chaos theory, which has proved efficient in explaining how something changes in time, was used to demonstrate the dependence of the tool life on the initial cutting conditions and thus contribute to a better understanding of the influence of the initial cutting condition on the tool life. Based on the chaotic tool wear model, the scatter wear dimension and Lyapunov exponents were found to be positive in all case of the initial cutting conditions such as initial speed, feed rate and depth of cut. The initial cutting speed appears however to have the most significant impact on tool life. In particular, the mathematical model was successfully applied to the case of machining TiMMCs. It was clearly shown that changing the initial cutting speed by 20 m/min for the first two seconds of machining instead of keeping it constant at 60 m/min during the whole cutting process leads to an increase in the tool life (up to 24%).


2014 ◽  
Vol 629 ◽  
pp. 487-492 ◽  
Author(s):  
Mohd Shahir Kasim ◽  
Che Hassan Che Haron ◽  
Jaharah Abd Ghani ◽  
E. Mohamad ◽  
Raja Izamshah ◽  
...  

This study was carried out to investigate how the high-speed milling of Inconel 718 using ball nose end mill could enhance the productivity and quality of the finish parts. The experimental work was carried out through Response Surface Methodology via Box-Behnken design. The effect of prominent milling parameters, namely cutting speed, feed rate, depth of cut (DOC), and width of cut (WOC) were studied to evaluate their effects on tool life, surface roughness and cutting force. In this study, the cutting speed, feed rate, DOC, and WOC were in the range of 100 - 140 m/min, 0.1 - 0.2 mm/tooth, 0.5 - 1.0 mm and 0.2 - 1.8 mm, respectively. In order to reduce the effect of heat generated during the high speed milling operation, minimum quantity lubrication of 50 ml/hr was used. The effect of input factors on the responds was identified by mean of ANOVA. The response of tool life, surface roughness and cutting force together with calculated material removal rate were then simultaneously optimized and further described by perturbation graph. Interaction between WOC with other factors was found to be the most dominating factor of all responds. The optimum cutting parameter which obtained the longest tool life of 60 mins, minimum surface roughness of 0.262 μm and resultant force of 221 N was at cutting speed of 100 m/min, feed rate of 0.15 mm/tooth, DOC 0.5 m and WOC 0.66 mm.


Author(s):  
Paolo Parenti ◽  
Francesco Puglielli ◽  
Massimo Goletti ◽  
Massimiliano Annoni ◽  
Michele Monno

AbstractSolid ceramic end mills for machining heat resistant super alloys (HRSA) have the potential to generate higher material removal rates, up to one order of magnitude, with respect to standard carbide tools. The machining operations in aerospace industry, where large removals are required to obtain tiny and slender parts like turbine blades, is a cost-intensive task that can benefit of the adoption of ceramic solid end mills. However, these tools show a quite limited tool life, especially when used with interrupted tool engagement strategies. Moreover, they might induce heat-related problems in the workpiece material surface integrity. This paper investigates the cutting and the tool wear during milling Inconel 718 with solid ø12 mm cutting end tool made by SiAlON. The wear mechanisms are studied together with their effects on process signals as cutting forces and power, measured via external and CNC integrated sensors. The carried experimental campaign allowed to find out that tool clogging and edge chipping were the primary cutting phenomena leading the tool wear. Cutting strategy (downmilling or upmilling) produced different results in terms of tool wear sensitivity and process outputs whereas upmilling configuration showed the best results in terms of cutting signals stability and surface integrity. At the same time, cutting speed was found to increase the cutting power more in upmilling than downmilling cutting. The analysis of the forces and power demonstrated that the typical tool wear mechanisms can be traced by signal monitoring due to their high impact on cutting processes. This fact shows the good potential of signal monitoring for a better tool life evaluation.


Titanium alloy is highly demanding in the aerospace industry due to its unique properties such are high strength-to-weight ratio and high thermal conductivity thus, made the material widely used in aerospace industries and excellent in its applications. However, those criteria’s become a crucial issue for machinists as titanium is categorized as difficult-to-machined material. High thermal conductivity caused shorten tool life because of the heat generated during machining was transferred directly to the cutting tool and leads to rapid tool wear. This experiment was conducted using 3 axis CNC Milling machine under wet cutting conditions. In order to identify the effect of step over, cutting speed and feed rate were fixed at constant values while step over (ae) values were varieties. The effect investigated were tool wear, wear mechanisms and tool failure modes. Tools experienced a longer tool life at low cutting speed of 60m/min, while chipping and notch wear appeared at high cutting speed 90m/min. The increasing of the step over value give less than 10% of the wear and reduced only 15% of machining time. With this, trochoidal milling proved that the step over give a minor contribution to wear while the dominant contribution was cutting speed followed by feed rate where the wear rate increased as the cutting speed increased.


Author(s):  
Richard Y. Chiou ◽  
Vitaliy Aynbinder ◽  
L. G. Stepanskiy ◽  
Lin Lu ◽  
Shreepud Rauniar ◽  
...  

Tool wear of machine tools and large usage of cutting fluids is one of the major problems in manufacturing. Cutting fluids are used to cool down the tool and have been shown to cause environmental problems in machine shops. Tool life and temperature have an inverse relationship, namely that the higher the temperature at the tool-chip interface is, the lower the tool life will be, and vice-versa. In this paper an innovative approach was taken to create an analytical solution to the effect of the embedded heat pipe on temperature of the tool and tool life. It has been well documented in the industry that the major factors that contribute to tool wear are the material properties of the tool insert and the work piece, cutting speed, depth of cut and feed rate. The analytical approach taken in this project is unique because it does not only take into account the complex boundary conditions of heat transfer but also the aforementioned factors and variety of possible cutting conditions. The analytical solution is in the form of set of equations which were developed to simulate the behavior of the tool insert under normal cutting conditions. Both cases, with and without heat-pipe were considered. The predicted temperature data was then compared to the existing experimental data, with very good results. In the end the project yields a quantitative evaluation on influence of mechanical properties of insert, work piece, heat pipe and cutting conditions on tool wear.


2011 ◽  
Vol 223 ◽  
pp. 381-390 ◽  
Author(s):  
Gianluca D'Urso ◽  
Aldo Attanasio

The present paper reports the results obtained investigating surface work hardening in turning as a function of cutting speed, feed rate and tool wear. An experimental campaign was carried out using AISI 304 steel as workpiece material. Pipes 4 mm thick were machined under orthogonal cutting conditions. Tools with flat rake surface were adopted and dry cutting conditions were taken into account. Cutting speed and feed rate were varied and the tool wear was monitored using a CNC visiomeasuring machine. The tool wear was related to the workpiece strain hardening. Starting from micro Vickers test data, an analytical model representing the strain hardening behavior along a workpiece section was defined. In addition, a Fortran subroutine for the simulation of strain hardening by means of a 2D FEM code was implemented.


2012 ◽  
Vol 504-506 ◽  
pp. 1305-1310 ◽  
Author(s):  
Antonio del Prete ◽  
Antonio Alberto de Vitis ◽  
Luigino Filice ◽  
Serafino Caruso ◽  
Domenico Umbrello

This paper reports the results of an experimental study of the tool wear and cutting forces in turning of Inconel 718 with coated carbide inserts. Inconel 718 is a difficult-to-cut nickel-based super-alloy commonly used in aerospace industry. The effects of cutting speed, feed rate and cutting tool geometry on tool wear have been widely analyzed in literature. Turning operations on complex components such as aircraft engines casings require the insert replacement at the end of each geometric feature manufacturing, independently from the actual tool wear level. For this reason, it is important to preserve tool integrity mainly in the most critical phase of operation (i.e., when the tool engages the workpiece). In fact, if the tool is damaged in this stage the quality of the whole operation is compromised. The attention has been focused on engage cutting conditions because the phenomenon that appears in this critical step plays a wide influence on tool integrity and, consequently, on the quality of the operation. For this purpose a nickel-based super alloy ring-workpiece, (Inconel 718), has been machined in lubricated cutting conditions by using a CNC lathe with carbide coated tools. Two variables have been investigated in this study: the Depth Of Cut (DOC) and the approaching Engage angle (En). In the studied working conditions Speed (S), Feed-rate (F) and removed volume (Vrim) were kept constant. Both tool wear and cutting forces evolution during cutting have been analyzed.


2013 ◽  
Vol 315 ◽  
pp. 241-245 ◽  
Author(s):  
Ali Davoudinejad ◽  
M.Y. Noordin ◽  
Danial Ghodsiyeh ◽  
Sina Alizadeh Ashrafi ◽  
Mohsen Marani Barzani

Hard turning is a dominant machining operation performed on hardened materials using single-point cutting tools. In recent years, hard turning operation has become more and more capable with respect to various machinability criteria. This work deals with machinability of hardened DF-3 tool steel with 55 ±1 HRC hardness at various cutting conditions in terms of tool life, tool wear mechanism and surface roughness. Continuous dry turning tests were carried out using coated, mixed ceramic insert with honed edge geometry. Two different cutting speeds, 100 and 210 m/min, and feed rate values of 0.05, 0.125 and 0.2 mm/rev were used with a 0.2 mm constant depth of cut for all tests. Additionally scanning electron microscope (SEM) was employed to clarify the different types of wear. As far as tool life was concerned, best result was achieved at lowest cutting condition whereas surface roughness values decreased when operating at higher cutting speed and lower feed rate. Additionally maximum volume of material removed is obtained at low cutting speed and high feed rate. Dominant wear mechanism observed during the experiments were flank and crater wear which is mainly caused by abrasive action of the hard workpiece material with the ceramic cutting tools.


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