Comparative Study of Material Damage and Tool Wear Mechanisms During Drilling of CFRP/Ti Stack

Author(s):  
Vijayathithan Mathiyazhagan ◽  
Anil Meena

Abstract The usage of CFRP and Ti stacks in the aerospace industry has widely increased due to its mechanical properties and improved structural functions but at the same time, different mechanical and thermal properties of the CFRP and Ti makes the process difficult. Major apprehensions in the drilling of CFRP/Ti stacks include rapid tool wear and poor hole quality. Typically, the surface quality of the holes in the drilling of CFRP/Ti stack is poor due to delamination, the progression of hole diameter in CFRP and burr formation in Ti. Moreover, the flank wear on the tool also influences the surface quality of the hole produced. Therefore, the present study is mainly focused on the influence of cutting parameters on cutting forces, hole quality and tool wear characteristics. Drilling was performed on CFRP/Ti stack using coated and uncoated carbide tools. The obtained results revealed a significant correlation between tool wear and delamination characteristics.

2014 ◽  
Vol 67 (3) ◽  
Author(s):  
H. Safari ◽  
S. Izman

Surface quality is one of the most critical restraints for determining cutting parameters and selecting of machining process in metal cutting process. In this study, the effects of cutting parameters and tool wear on the surface and sub-surface quality of high speed dry end milling Ti-6Al-4V were investigated. PVD Coated carbide tools were used under different high cutting speeds and feed rates. The quality of the machined surface and corresponding alteration on the sub-surface and entry/exit edges were characterized through scanning electron microscopy. The results showed that the better surface quality was obtained when machining at higher cutting speeds and feed rates. High speed dry end milling using the worn tool causes to plastic deformation of the alloy which is resulted in developing the lamellae on the surface and causing poor surface finish. Worn tools with the uniform tool wear land generated better surface quality compare to those with chipping and flaking on the tool edge surface. Tool wear is suggested as the other contributing factor in developing entry and exit edge damages. The results of sub-surface alteration measurement revealed that the worn tool enhanced the sub-surface alteration resulted in 45% increase in plastic deformation compare to the new tool.


2013 ◽  
Vol 698 ◽  
pp. 107-116 ◽  
Author(s):  
Yann Landon ◽  
Mehdi Cherif

Assembling composite structures requires a significant number of drillings. During machining, defects appear on the surface of the drilled hole. This paper outlines that the criterion Ra is not adapted to reliably characterize the surface quality on composites. In particular, various tests have shown significant variations of the value of Ra according to the angular position of measurement, as well as the filtering artefacts. This study puts forward a new methodology to characterize the surface quality of a composite hole. To this end, a study of sensitivity of the various criteria proposed by standard ISO4287 was conducted. Various geometries of tool are also tested in the experimental phase. The impact of cutting parameters and tool wear are analyzed based on this new methodology.


2020 ◽  
Vol 15 ◽  
Author(s):  
Lei Li ◽  
Yujun Cai ◽  
Guohe Li ◽  
Meng Liu

Background: As an important method of remanufacturing, laser cladding can be used to obtain the parts with specific shapes by stacking materials layer by layer. The formation mechanism of laser cladding determines the “Staircase effect”, which makes the surface quality can hardly meet the dimensional accuracy of the parts. Therefore, the subsequent machining must be performed to improve the dimensional accuracy and surface quality of cladding parts. Methods: In this paper, chip formation, cutting force, cutting temperature, tool wear, surface quality, and optimization of cutting parameters in the subsequent cutting of laser cladding layer are analyzed. Scholars have expounded and studied these five aspects but the cutting mechanism of laser cladding need further research. Results: The characteristics of cladding layer are similar to that of difficult to machine materials, and the change of parameters has a significant impact on the cutting performance. Conclusion: The research status of subsequent machining of cladding layers is summarized, mainly from the aspects of chip formation, cutting force, cutting temperature, tool wear, surface quality, and cutting parameters optimization. Besides, the existing problems and further developments of subsequent machining of cladding layers are pointed out. The efforts are helpful to promote the development and application of laser cladding remanufacturing technology.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 958
Author(s):  
Francisco Javier Trujillo Vilches ◽  
Sergio Martín Béjar ◽  
Carolina Bermudo Gamboa ◽  
Manuel Herrera Fernández ◽  
Lorenzo Sevilla Hurtado

Geometrical tolerances play a very important role in the functionality and assembly of parts made of light alloys for aeronautical applications. These parts are frequently machined in dry conditions. Under these conditions, the tool wear becomes one of the most important variables that influence geometrical tolerances. In this work, the influence of tool wear on roundness, straightness and cylindricity of dry-turned UNS A97075 alloy has been analyzed. The tool wear and form deviations evolution as a function of the cutting parameters and the cutting time has been assessed. In addition, the predominant tool wear mechanisms have been checked. The experimental results revealed that the indirect adhesion wear (BUL and BUE) was the main tool-wear mechanism, with the feed being the most influential cutting parameter. The combination of high feed and low cutting speed values resulted in the highest tool wear. The analyzed form deviations showed a general trend to increase with both cutting parameters. The tool wear and the form deviations tend to increase with the cutting time only within the intermediate range of feed tested. As the main novelty, a relationship between the cutting parameters, the cutting time (and, indirectly, the tool wear) and the analyzed form deviations has been found.


2011 ◽  
Vol 299-300 ◽  
pp. 1016-1019
Author(s):  
Tie Jun Li ◽  
Jing Tang ◽  
Li Jun Yan ◽  
Yang Wang

This paper presented the experiments of Nd:YAG pulsed laser cutting of titanium alloy, super-alloy and stainless steel sheet, and investigated the influences of different laser cutting parameters on the surface quality factors focusing surface morphology. In comparison with air-, argon- and nitrogen-assisted laser cutting, argon-assisted laser cutting comes with unaffected surface quality and is suitable for laser cutting with subsequent welding requirement. With analyzing the interaction between pulses overlapping rate and energy, the results show that medium pulse overlapping rate and lower pulse rate helps to improve the surface roughness with pulsed laser cutting. And the results would be beneficial to find optimum cutting parameters for good separation surface.


2020 ◽  
Vol 10 (5) ◽  
pp. 1667 ◽  
Author(s):  
Basem M. A. Abdo ◽  
Abdualziz El-Tamimi ◽  
Emad Abouel Nasr

Pocket milling has been regarded as one of the most widely used operations in machining. The surface quality of the machined pockets is an essential aspect of any engineering and medical applications. In the current study, rotary ultrasonic machining (RUM) was applied for milling micro-pockets on alumina (Al2O3) ceramic. The objective of this research was to analyze the effect of the tool overlapping parameters on the surface roughness, surface morphology and the profiles of the machined pockets. Subsequently, the effect of different tool path strategies was analyzed on the surface quality and the material removal rate (MRR) of the machined pockets. A scanning electron microscope is used for analyzing the tool wear mechanisms. The experimental results provide evidence that the surface roughness, surface morphology and the MRR have been significantly affected by the considered tool overlapping and the tool path strategies. Furthermore, among the selected tool overlapping parameters (5–25%) and the tool path strategies, the best surface roughness (Ra = 0.155 μm and Rt = 1.432 µm) of the machined pockets can be found at 20% of the tool overlapping with a mix of uni-directional and zigzag tool path strategy.


Author(s):  
Ferial Hakami ◽  
Alokesh Pramanik ◽  
Animesh K Basak

Higher tool wear and inferior surface quality of the specimens during machining restrict metal matrix composites’ application in many areas in spite of their excellent properties. The researches in this field are not well organized, and knowledge is not properly linked to give a complete overview. Thus, it is hard to implement it in practical fields. To address this issue, this article reviews tool wear and surface generation and latest developments in machining of metal matrix composites. This will provide an insight and scientific overview in this field which will facilitate the implementation of the obtained knowledge in the practical fields. It was noted that the hard reinforcements initially start abrasive wear on the cutting tool. The abrasion exposes new cutting tool surface, which initiates adhesion of matrix material to the cutting tool and thus causes adhesion wear. Built-up edges also generate at lower cutting speeds. Although different types of coating improve tool life, only diamond cutting tools show considerably longer tool life. The application of the coolants improves tool life reasonably at higher cutting speed. Pits, voids, microcracks and fractured reinforcements are common in the machined metal matrix composite surface. These are due to ploughing, indentation and dislodgement of particles from the matrix due to tool–particle interactions. Furthermore, compressive residual stress is caused by the particles’ indentation in the machined surface. At high feeds, the feed rate controls the surface roughness of the metal matrix composite; although at low feeds, it was controlled by the particle fracture or pull out. The coarser reinforced particles and lower volume fraction enhance microhardness variations beneath the machined surface.


2017 ◽  
Vol 24 (Supp02) ◽  
pp. 1850033
Author(s):  
WENYONG SHI ◽  
YAN MA ◽  
CHUNMEI YANG ◽  
BIN JIANG ◽  
ZHE LI

Milling processing is an important way to obtain wood–polyethylene composite (WPC) end products. In order to improve the processing efficiency and surface quality of WPC and meet the practical application requirements, this paper focussed on morphology and roughness of the WPC-milled surface and studied surface quality changes under different cutting parameters and milling methods through multi-parameters milling experiments. The milling surface morphology and roughness of WPC were analyzed and measured during cut-in, cutting and cut-out sections. It also revealed the affect rule of different cutting parameters and milling methods on milled surface morphology and roughness. The results show that the milling surface roughness of WPC products with wood powder content of 70% is significantly larger than the one whose wood powder content is 60%, and defects such as holes are also relatively more. Finally, a surface roughness prediction model was established based on the mathematical regression method and its multi-factor simulation was carried out. A comparative analysis of predictive and experimental values was performed to verify the reliability of the model. It could also provide theoretical guidance and technical guarantee for high processing quality of WPC milling and cutting.


2015 ◽  
Vol 760 ◽  
pp. 475-481
Author(s):  
Cristina Biris ◽  
Octavian Bologa ◽  
Claudia Girjob ◽  
Sever Gabriel Racz

This paper presents the study of the influence of cutting parameters on surface quality in laser cutting of metallic materials. In this paper, it is shown which of the cutting parameters have the greatest influence on the quality of the processed surfaces by measuring various roughness parameters. After the experimental research was carried out a ranking of the factors of influence on the response functions was made, also graphs of dependency to various parameters of roughness were made.


2013 ◽  
Vol 770 ◽  
pp. 74-77 ◽  
Author(s):  
Jin Xing Kong ◽  
Liang Li ◽  
Dong Ming Xu ◽  
Ning He

Pure iron is a kind of high plasticity and toughness material. In the process of cutting pure iron, the tool wear is very serious. In this paper, three kinds of cutting tools KC5010, K313 and 1105 are used in the cutting pure iron process and the tool wear tests in dry cutting condition with different cutting parameters have been carried out. According to the results, the tool wear mechanisms and tool life of three kinds of cutting tools have been compared and analyzed. It is concluded that the tool life of K313 is better than KC5010 and 1105 and the three kinds of tool mechanisms are primarily adhesion wear, diffusion wear and oxidation wear.


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