scholarly journals Wear Behavior of Uncoated and Coated Tools in Milling Operations of AMPCO (Cu-Be) Alloy

2021 ◽  
Vol 11 (16) ◽  
pp. 7762
Author(s):  
Vitor F. C. Sousa ◽  
João Castanheira ◽  
Francisco J. G. Silva ◽  
José S. Fecheira ◽  
Gustavo Pinto ◽  
...  

Copper-Beryllium alloys have excellent wear resistance and high mechanical properties, they also possess good electrical and thermal conductivity, making these alloys very popular in a wide variety of industries, such as aerospace, in the fabrication of tools for hazardous environments and to produce injection molds and mold inserts. However, there are some problems in the processing of these alloys, particularly when these are subject to machining processes, causing tools to deteriorate quite rapidly, due to material adhesion to the tool’s surface, caused by the material’s ductile nature. An assessment of tool-wear after machining Cu-Be alloy AMPCOLOY 83 using coated and uncoated tools was performed, offering a comparison of the machining performance and wear behavior of solid-carbide uncoated and DLC/CrN multilayered coated end-mills with the same geometry. Multiple machining tests were conducted, varying the values for feed and cutting length. In the initial tests, cutting force values were registered. The material’s surface roughness was also evaluated and the cutting tools’ edges were subsequently analyzed, identifying the main wear mechanisms and how these developed during machining. The coated tools exhibited a better performance for shorter cutting lengths, producing a lower degree of roughness on the surface on the machined material. The wear registered for these tools was less intense than that of uncoated tools, which suffered more adhesive and abrasive damage. However, it was observed that, for greater cutting lengths, the uncoated tool performed better in terms of surface roughness and sustained wear.

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1783
Author(s):  
Hamza A. Al-Tameemi ◽  
Thamir Al-Dulaimi ◽  
Michael Oluwatobiloba Awe ◽  
Shubham Sharma ◽  
Danil Yurievich Pimenov ◽  
...  

Aluminum alloys are soft and have low melting temperatures; therefore, machining them often results in cut material fusing to the cutting tool due to heat and friction, and thus lowering the hole quality. A good practice is to use coated cutting tools to overcome such issues and maintain good hole quality. Therefore, the current study investigates the effect of cutting parameters (spindle speed and feed rate) and three types of cutting-tool coating (TiN/TiAlN, TiAlN, and TiN) on the surface finish, form, and dimensional tolerances of holes drilled in Al6061-T651 alloy. The study employed statistical design of experiments and ANOVA (analysis of variance) to evaluate the contribution of each of the input parameters on the measured hole-quality outputs (surface-roughness metrics Ra and Rz, hole size, circularity, perpendicularity, and cylindricity). The highest surface roughness occurred when using TiN-coated tools. All holes in this study were oversized regardless of the tool coating or cutting parameters used. TiN tools, which have a lower coating hardness, gave lower hole circularity at the entry and higher cylindricity, while TiN/TiAlN and TiAlN seemed to be more effective in reducing hole particularity when drilling at higher spindle speeds. Finally, optical microscopes revealed that a built-up edge and adhesions were most likely to form on TiN-coated tools due to TiN’s chemical affinity and low oxidation temperature compared to the TiN/TiAlN and TiAlN coatings.


Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 841
Author(s):  
Yanmei Liu ◽  
Tie-Gang Wang ◽  
Wei Lin ◽  
Qiang Zhu ◽  
Bing Yan ◽  
...  

Aluminum rich nitride coatings are often used to protect cutting tools and prolong their service life. In this work, a preoxidation technique and duplex coating design were combined to further improve the bearing capacity and heat resistance of cutting tools. The Al-Cr-Si-N, Al-Cr-Si-O-N, and Al-Cr-Si-N/Al-Cr-Si-O-N duplex coatings were developed by arc ion plating, respectively. The morphology, phase constituents, mechanical and tribological properties of the coatings were characterized and tested by SEM, XRD, a micro-hardness tester, scratch tester, and tribometer. The results showed the coating became more compact and smoother after oxygen doping. However, the Al-Cr-Si-N coating presented the best mechanical properties and tribological behaviors. Its hardness and critical load showed the highest values, which were about 4000 HV and 81 N, respectively. A friction coefficient of 0.67 and wear rate of 1.4 × 10−3 μm3/N·mm were also the lowest values in the study. The three coatings were deposited on the same solid carbide end mills and performed the cutting tests under same conditions. By comparison, the Al-Cr-Si-N coated tool presented the longest tool life and minimum cutting force when cutting C1045 medium-carbon steel. After 90 min of dry milling, the width of the flank wear band (VB) of the AlCrSiN coated tool reached 135 μm, which was much lower than that of the other two coated tools.


2018 ◽  
Vol 7 (2.32) ◽  
pp. 143
Author(s):  
Thella Babu Rao ◽  
Venu Pilli ◽  
Nallamotu Revanth Sai Venkat ◽  
Nagandla Pavan ◽  
Thalari Shiva Ram

This paper presents optimization of plasma heat assisted turning process for machining hardened EN24 die steel (53HRC) by using gray relational analysis. Flank wear and surface roughness (Ra) are experimentally measured as the process performance characteristics under varying conditions of preheating temperature, cutting speed and cutting length. The plasma heating approach was implemented to preheat the workpiece. The machining experiments were conducted according to the L16 design of experiments. Since the chosen machining performance indicators are found with confliction for the chosen process variables, the problem is treated as multi-response optimization problem to minimize the tool wear and surface roughness simultaneously. Therefore, the problem was solved by implementing the gray relational analysis and the derived optimal machining conditions were analysed and reported.  


2019 ◽  
Vol 945 ◽  
pp. 556-562
Author(s):  
A.G. Kondrashov ◽  
D.T. Safarov ◽  
R.R. Kazargeldinov

Minimizing energy consumption in the processing of parts on metal-cutting equipment is most effective at the stage of designing the content of operations. Important in this process is the precise determination of the initial parameters - cutting forces. This parameter allows you to plan both energy consumption and perform additional calculations for the deformation of the tooling and workpiece in order to predict the geometric accuracy of the machined part. The article presents the results of experiments on measuring the circumferential cutting force during milling operations of an aluminum alloy workpiece with an end mill. The measurements were carried out by an indirect method - by recording the electrical power on the spindle and then calculating the circumferential cutting force. Theoretical analysis of the methods of calculation of cutting forces showed significant differences between the results obtained by domestic methods and recommendations of world manufacturers of cutting tools. Statistical analysis of the results of calculations based on reference data and measurements made it possible to assess the adequacy of the known methods for calculating cutting forces in order to minimize energy consumption in operations of processing parts on metal-cutting equipment


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.


2009 ◽  
Vol 626-627 ◽  
pp. 11-16 ◽  
Author(s):  
Yung Cheng Wang ◽  
Chen Hsiang Chen ◽  
Bean Yin Lee

Due to the rapid development in recent cutting technology, demands for different types of precise cutting tools become increasingly complicated. Since the design and grinding of end-mills are the last and the most important processing for cutting tools. The geometrical accuracy and the cutting performance of an end-mill depend essentially on the grinding. However, the complicated geometry of an end-mill will be ground by the specific software of CAD/CAM on the 5-axis CNC tool grinding machine. The precision of end-mill grinder will be determined by the performance of 5-axis CNC tool grinder and setting of grinding parameters. Three regulation factors for grinding are grit size of the diamond grinding wheel, grinding speed and the feeding speed. The variable ranges of each parameter can be divided in large, medium and small interval. In this study for an end-mill with fixed geometrical profile, a series of different grinding parameters have been utilized by the 33 factorial experiment planning. And tool grinding experiments for the rod material specification of tungsten carbide have been performed by 5-axis CNC tool grinder. After grinding, surface roughness of tools will be measured. The reliability and precision of the end-mill grinding can be enhanced by the prediction model of polynomial network for surface roughness of end-mills. Besides, the database system for cutting tool has benn established. Totally 4802 data were constructed in the relational database according to the characteristics of tools.


2013 ◽  
Author(s):  
A. B. Koteswara Rao ◽  
Sanjay Darvekar ◽  
K. Ramji

This paper presents the impact of workpiece location on the machining performance of a 2-degree of freedom Parallel Kinematic Machine (PKM) tool. The PKM behavior is highly non-uniform and depends on the tool position within the workspace. The structural deformation and vibration due to cutting loads affect the quality of machined surfaces. The aim of the present study is to find the optimal tool position (workpiece location) where the workpiece is machined to a specific quality level. End-milling operations are carried out at various locations within the workspace and the surface roughness of machined surface (Ra) is measured at each location. A regression model is developed to predict the surface roughness. The study shows that the workpiece location has significant impact upon surface roughness of the machined part. Finally, a suitable workspace is defined for end-milling operation.


2021 ◽  
pp. 15-19
Author(s):  
M. Sh. Migranov ◽  
A.M. Migranov

The results of theoretical and experimental studies of tribological characteristics of composite multilayer coatings for cutting tools for blade processing by milling are presented. Installed reducing the coefficient of friction, longer tool life and reduced thermal loading of the cutting zone in milling operations with the use of wear-resistant coatings.


2010 ◽  
Vol 438 ◽  
pp. 203-209 ◽  
Author(s):  
Fritz Klocke ◽  
Susanne Eva Cordes ◽  
Klaus Gerschwiler

The machining of difficult-to-cut materials such as nickel-based alloys and austenitic steels are focus in a lot of investigations for a long time. When machining these materials, different effects are overlapping. Approaches to overcome the several problems when machining these materials can be an appropriate coating system for the cutting tool as well as innovative lubricants. Coatings are one of the most common possibilities to improve the cutting performance of tools, notably the tool life as well as the material removal rate. Aluminium oxide coatings made by Physical Vapour Deposition (PVD) technology is a promising coating material for cutting operations. Due to its outstanding characteristics, such as high hardness, high thermal stability and low tendency to adhesion aluminium oxide is a predestined material for the machining of difficult-to-cut materials. In combination with innovative environmental friendly lubricants, the performance of cutting tools is increasing significantly. The objective of this work is to study the wear mechanisms and the cutting performance of aluminium oxide based coated tools in turning, drilling and milling operations.


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