Experimental Analysis of Wear Mechanism and Tool Life in Dry Drilling of Al2024

2012 ◽  
Vol 566 ◽  
pp. 217-221 ◽  
Author(s):  
Ali Davoudinejad ◽  
Sina Alizadeh Ashrafi ◽  
Raja Ishak Raja Hamzah ◽  
Abdolkarim Niazi

Aluminum alloy is widely used in industry and various researches has been done on machiability of this material mainly due to its low weight and other superior properties. Dry machining is still interesting topic to reduce the cost of manufacturing and environmental contaminations. In present study dry machining of Al 2024 investigated on tool life, tool wear mechanisms, hole quality, thrust force and torque. Different types of high speed steel (HSS) tools utilized at constant feed rate of 0.04 mm/rev and cutting speeds within the range of 28 and 94 m/min. Experimental results revealed that HSCo drills, performed better than HSS drills in terms of tool life and hole quality. The main wear mechanisms which analyzed by scanning electron microscope found abrasive and adhesion wear on flank face, besides, BUE observed at chisel and cutting edges. However tool wear and BUE formation found more significant at high cutting speed. In terms of thrust force, two facet HSCo tools, recorded higher thrust force than four facet HSS drills.

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.


2018 ◽  
Vol 51 (9-10) ◽  
pp. 417-430 ◽  
Author(s):  
Zülküf Demir

The differences in the cutting speed are a serious problem along the cutting edge of the drill, in drilling operations. This problem can partly be solved reducing the length of the cutting edge via changing the drill point angle. In addition, in this study, the effect of point angle, feed rate, and cutting speed on drilling is investigated. For identifying the optimum cutting parameters, AISI 1050 steel alloy was selected as the experimental specimen, these specimen were pre-drilled 5 mm in diameter due to eliminating the effect of the chisel edge. In the experiments, the holes were drilled only at a depth of 10 mm in order not to give any harm to the dynamometer while measuring thrust force. For this aim, in drilling process, drills with point angle of 100°, 118°, 136°, 154°, and 172° were selected. In conclusion, the thrust force, the tool wear, and the surface roughness linearly decreased with increasing point angles due to less removal chip area, in per revolve of the tool. However, the thrust force, the tool wear, and the surface roughness were adversely affected at higher feed rates and lower cutting speeds. The hole dimensional accuracy decreased at lower feed rates and cutting speeds but at higher point angles and concurrently at higher feed rates but lower point angles and cutting speeds. However, the hole dimensional accuracy showed more decisiveness at 118° than other point angles, while the highest dimensional accuracy values recorded at 136° point angle, at higher cutting speeds.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5011
Author(s):  
Cécile Escaich ◽  
Zhongde Shi ◽  
Luc Baron ◽  
Marek Balazinski

The TiC particles in titanium metal matrix composites (TiMMCs) make them difficult to machine. As a specific MMC, it is legitimate to wonder if the cutting mechanisms of TiMMCs are the same as or similar to those of MMCs. For this purpose, the tool wear mechanisms for turning, milling, and grinding are reviewed in this paper and compared with those for other MMCs. In addition, the chip formation and morphology, the material removal mechanism and surface quality are discussed for the different machining processes and examined thoroughly. Comparisons of the machining mechanisms between the TiMMCs and MMCs indicate that the findings for other MMCs should not be taken for granted for TiMMCs for the machining processes reviewed. The increase in cutting speed leads to a decrease in roughness value during grinding and an increase of the tool life during turning. Unconventional machining such as laser-assisted turning is effective to increase tool life. Under certain conditions, a “wear shield” was observed during the early stages of tool wear during turning, thereby increasing tool life considerably. The studies carried out on milling showed that the cutting parameters affecting surface roughness and tool wear are dependent on the tool material. The high temperatures and high shears that occur during machining lead to microstructural changes in the workpiece during grinding, and in the chips during turning. The adiabatic shear band (ASB) of the chips is the seat of the sub-grains’ formation. Finally, the cutting speed and lubrication influenced dust emission during turning but more studies are needed to validate this finding. For the milling or grinding, there are major areas to be considered for thoroughly understanding the machining behavior of TiMMCs (tool wear mechanisms, chip formation, dust emission, etc.).


Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 464
Author(s):  
Alain Gil Del Val ◽  
Fernando Veiga ◽  
Octavio Pereira ◽  
Luis Norberto Lopez De Lacalle

Threading holes using tapping tools is a widely used machining operation in the industry. This manufacturing process involves a great tool immersion in the part, which involves both friction and cutting. This makes the use of coatings critical to improving tool life. Four coatings are used based on Physical vapor deposition (PVD) technology—TiN, TiCN, TiAlN and TiAlN+WC/C are compared to uncoated tool performance. The effect of various coatings on the life of M12 × 1.5 tapping tools during threading of through holes 20 mm deep, in GG25 casting plates, dry and applying cutting speed of 50 m/min. The end-of-life criterion has been established based on a cutting torque of 16 N-m. Taking the uncoated tap as a basis for comparison, it is observed that coatings based on PVD technologies increase tool life doubling in the most advantageous case with the TiAlN coating. PVD type coatings provide better protection to wear at cylindrical area of the tool, where the thread profile is finished, than uncoated taps. The teeth located in the cone-cylinder transition zone of the taps suffer the most wear regardless of the coating. However, taps coated with TiAlN+WC/C wear level values is lowest of all the coatings tested, which indicates a strong reinforcement in these teeth.


Author(s):  
Justin L. Milner ◽  
Jeffrey A. Beers ◽  
John T. Roth

Machining is a popular and versatile manufacturing process that is widely used in today’s industry when producing metallic parts; however, limited tool life can make this an expensive and time consuming fabrication technique. Consequently, methods that decrease the rate of tool wear and, thus, increase tool longevity are a vital component when improving the efficiency of machining processes. To this end, cryogenically treating cutting tools (especially high-speed steel tooling) is becoming more commonplace since research has shown that the treated tooling exhibits significantly higher wear resistance. At this point, however, the effect of cryogenic treatments on ceramic tooling has not been established. Considering this, the research herein presents a feasibility study on the effectiveness of using cryogenic treatments to enhance the wear resistance of WG-300 whisker-reinforced ceramic cutting inserts. To begin, the effect of the cryogenic treatment on the insert’s hardness is examined. Subsequently, tool wear tests are conducted at various cutting speeds. Through this study, it is shown that cryogenically treating the ceramic inserts decreases the rate of tool wear at each of the cutting speeds that were tested. However, the degree of wear resistance introduced by cryogenically treating the inserts proved to be highly dependent on the cutting speed, with slower speeds exhibiting greater improvements. Thus, based on this initial study, the cryogenic treatment of ceramic tooling appears to produce beneficial results, potentially increasing the overall efficiency of machining processes.


2012 ◽  
Vol 488-489 ◽  
pp. 724-728 ◽  
Author(s):  
Tadahiro Wada

Using polycrystalline cubic boron nitride compact (cBN) tools, which have different cBN contents and cBN particle sizes, the influences of both the cBN content and the cBN particle size on tool wear in turning of hardened steel at various cutting speeds was experimentally investigated. Three types of cBN tools (a cBN content of 45-55% and 75%, and a cBN particle size of 0.5 μm and 5 μm, respectively) were tested. Furthermore, three kinds of chamfered and honed cutting edges were also used. The main results obtained are as follows: (1) In the case of the cBN tools with the same cBN particle size of 5.0 μm, the tool life of the cBN tool with a cBN content of 75% was longer than that of the cBN tool with a cBN content of 45% at low cutting speed. However, at high cutting speed, the tool life of the cBN tool with a cBN content of 75% was shorter. (2) The tool life of the cBN tool with both a cBN content of 55% and a cBN particle size of 0.5 μm was the longest. (3) The tool wear of cBN tools decreased with a decrease in chamfer width.


2013 ◽  
Vol 773-774 ◽  
pp. 339-347 ◽  
Author(s):  
Muhammad Yusuf ◽  
M.K.A. Ariffin ◽  
N. Ismail ◽  
S. Sulaiman

With increasing quantities of applications of Metal Matrix Composites (MMCs), the machinablity of these materials has become important for investigation. This paper presents an investigation of surface roughness and tool wear in dry machining of aluminium LM6-TiC composite using uncoated carbide tool. The experiments carried out consisted of different cutting models based on combination of cutting speed, feed rate and depth of cut as the parameters of cutting process. The cutting models designed based on the Design of Experiment Response Surface Methodology. The objective of this research is finding the optimum cutting parameters based on workpiece surface roughness and cutting tool wear. The results indicated that the optimum workpiece surface roughness was found at high cutting speed of 250 m min-1 with various feed rate within range of 0.05 to 0.2 mm rev-1, and depth of cut within range of 0.5 to 1.5 mm. Turning operation at high cutting speed of 250 m min-1 produced faster tool wear as compared to low cutting speed of 175 m min-1 and 100 m min-1. The wear minimum (VB = 42 μm ) was found at cutting speed of 100 m min-1, feet rate of 0.2 mm rev-1, and depth of cut of 1.0 mm until the length of cut reached 4050 mm. Based on the results of the workpiece surface roughness and the tool flank wear, recommended that turning of LM6 aluminium with 2 wt % TiC composite using uncoated carbide tool should be carried out at cutting speed higher than 175 m min-1 but at feed rate of less than 0.05 mm rev-1 and depth of cut less than 1.0 mm.


2020 ◽  
Vol 17 (5) ◽  
pp. 661-674 ◽  
Author(s):  
Sathiyamoorthy Margabandu ◽  
Senthilkumar Subramaniam

Purpose This paper aims to deal with the influence of cutting parameters on drill thrust force, delamination and surface roughness in the drilling of laminated jute/carbon hybrid composites. Design/methodology/approach The hybrid composites were fabricated with four layers of fabrics, which are arranged in different sequences using the hand-layup technique. Drilling experiments involved drilling of 6 mm diameter holes on the prepared composite plates using high-speed steel and solid carbide drill materials. Analysis of variance was used to find the influence, percentage contribution and significance of drilling parameters on drilling-induced damages. Scanning electron microscopy analysis was also conducted to understand the fracture behavior and surface morphology of the drilled holes. Findings The experimental study reveals that the most significant effect was the feed rate influenced the drill thrust force and the drill speed influenced both delamination factor and surface roughness of hybrid fiber-reinforced composites. From observations, the suggested combination for drilling jute/carbon hybrid composites is carbide drill, spindle speed of 1,750 rpm and feed of 0.03 mm/rev. Originality/value The new lightweight and low-cost hybrid composites were developed by hybridizing jute with carbon fabrics in the epoxy matrix with interplay arrangements. The influence of cutting speed and feed rate on delamination damage and surface roughness in the drilling of hybrid composites have been experimentally evaluated.


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