Ductile Regime Scratching of a Rock Sample in a Laser Assisted Machining Technique

2017 ◽  
Author(s):  
Barkin Bakir ◽  
Hossein Mohammadi ◽  
John A. Patten

Rocks are playing an important role in the life of mankind since ancient times. One of the most significant characteristics of the rocks is their brittleness, which makes them exhibit a very poor machinability and usually severe fracture results during machining. In this paper, Micro-Laser Augmented Machining (μ-LAM) technique is applied on scratching a commercial rock, Gabbro-Labradorite, which is a composite of grained natural minerals such as feldspar, magnetite and mica. In the μ-LAM process, a laser is used to locally heat and thermally soften the materials below the scratching tool during the machining operation. In this paper, scratching tests have been done on the Gabbro-Labradorite minerals, with and without laser heating and results are compared and reported. Micro-laser assisted scratch tests (with an actual cutting tool) were successful in demonstrating the enhanced thermal softening of the feldspar and magnetite minerals. The effect of the laser power was studied by measuring the depths of the cuts for the scratch tests. When generating the scratches with a diamond tool, load range was increased from 50 to 500 mN. Laser powers of 10, 15, 20, and 25 Watt (W) have been utilized. All the tests were repeated two times to increase the reliability of the results. 3D profiles were generated by using a white light interferometer and microscopic images of the cuts have been reported. Results show that Ductile to Brittle Transition (DBT) depth, which is the critical depth for machining brittle materials, increased with the aid of the laser. Results are very important for the machining of the Gabbro-Labradorite to get a high material removal rate (MRR), low tool wear and better surface quality.

Author(s):  
J Kang ◽  
M Hadfield

Hot isostatically pressed silicon nitride ball blanks were lapped from a diameter of 13.255 mm to a diameter of 12.7 mm by a novel eccentric lapping machine. A maximum material removal rate of 68 μm/h has been achieved under a nominal lapping load of 43 N per ball. It was found that the material removal rate increased almost linearly with the lapping load within this load range. When the lapping load was higher than 43 N per ball, the material removal rate started to drop and the lapped ball roundness error started to increase. At the highest nominal lapping load of 107 N per ball, surface damage and subsurface damage were found on the lapped balls. Because of the eccentric loading effect, the actual load on an individual ball could be 25–28 per cent higher than the nominal lapping load. The surface residual stresses of lapped balls under different lapping loads were measured, and it was found that the lapping load had less effect than the previous hot isostatic pressing process. Rolling contact fatigue tests were conducted on balls lapped at nominal loads of 43 and 107 N per ball. No failure occurred on the ball lapped at 43 N per ball after 138 × 106 stress cycles. The ball lapped at 107 N per ball failed after 13.3 x 106 stress cycles with a shallow spall with a flat bottom inside. This research suggests that the lapping load for advanced ceramic balls in conventional concentric lapping could be doubled from 20 to 40 N per ball without degrading the surface quality of lapped balls.


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 208
Author(s):  
Xuefeng Yan ◽  
Shuliang Dong ◽  
Xianzhun Li ◽  
Zhonglin Zhao ◽  
Shuling Dong ◽  
...  

Zirconia ceramics are widely used in many fields because of their excellent physical and mechanical properties. However, there are some challenges to machine zirconia ceramics with high processing efficiency. In order to optimize parameters for milling zirconia ceramics by polycrystalline diamond tool, finite element method was used to simulate machining process based on Johnson-Cook constitutive model. The effects of spindle speed, feed rate, radial and axial cutting depth on cutting force, tool flank wear and material removal rate were investigated. The results of the simulation experiment were analyzed and optimized by the response surface method. The optimal parameter combination was obtained when the spindle speed, feed rate, radial and axial cutting depth were 8000 r/min, 90.65 mm/min, 0.10 mm and 1.37 mm, respectively. Under these conditions, the cutting force was 234.81 N, the tool flank wear was 33.40 μm when the milling length was 60 mm and the material removal rate was 44.65 mm3/min.


2006 ◽  
Vol 304-305 ◽  
pp. 81-84
Author(s):  
Ai Bing Yu ◽  
A.J. Wang ◽  
C.G. Luan ◽  
S.F. Chen

Bonds of electroplated diamond tools are investigated through the studies of microstructures and properties. Three coatings for tool bonds, nickel, nickel-cobalt and bright nickel, were fabricated with electrodeposition processes, and were heat-treated with different temperatures. The hardness and microstructures of coatings were measured and observed. Optical glass K9 was machined with fabricated electroplated diamond tools to compare material removal rate and grinding ratio. The grain sizes of three bond coatings are different. The laminar structures of nickel-cobalt and bright nickel coatings turn to fine columnar structure after heat treatment processes. With heat treatment of 200°C temperature, bright nickel electroplated diamond tool presents highest values of material removal rate and grinding ratio. The research results show that better microstructures and property of bond for electroplated diamond tool can be obtained by selecting proper electroplating technology and heat treatment processes.


2009 ◽  
Vol 1157 ◽  
Author(s):  
Sarah Neyer ◽  
Burak Ozdoganlar ◽  
C. Fred Higgs

AbstractWith the increase in integrated circuit (IC) feature density, the quality of chemical mechanical polishing (CMP) becomes more important as the copper interconnects decrease in size. The optimization of the IC manufacturing process will be greatly enhanced if the nanoscale effects on CMP are better understood. CMP-related wear at the sub-micron scale, where a single particle affects the microstructure of individual copper features within the substrate, needs to be investigated to account for wafer-scale variations. Hardness is known to affect the material removal rate, but the grain level mechanism of the removal process is not yet well known. In this work, the orientation-dependence of wear has been investigated by performing nanoscale scratch tests on single crystal copper along different crystallographic planes, indentified using orientation imaging microscopy (OIM). An analysis of the surface forces and post-scratch topography produced during the scratch tests was conducted and the results have been interpreted from a CMP perspective. Ultimately, these results are expected to refine existing material removal rate models which do not consider the sensitivity of microstructure on the CMP process.


Author(s):  
Amritpal Singh ◽  
Rakesh Kumar

In the present study, Experimental investigation of the effects of various cutting parameters on the response parameters in the hard turning of EN36 steel under the dry cutting condition is done. The input control parameters selected for the present work was the cutting speed, feed and depth of cut. The objective of the present work is to minimize the surface roughness to obtain better surface finish and maximization of material removal rate for better productivity. The design of experiments was done with the help of Taguchi L9 orthogonal array. Analysis of variance (ANOVA) was used to find out the significance of the input parameters on the response parameters. Percentage contribution for each control parameter was calculated using ANOVA with 95 % confidence value. From results, it was observed that feed is the most significant factor for surface roughness and the depth of cut is the most significant control parameter for Material removal rate.


Author(s):  
A. Pandey ◽  
R. Kumar ◽  
A. K. Sahoo ◽  
A. Paul ◽  
A. Panda

The current research presents an overall performance-based analysis of Trihexyltetradecylphosphonium Chloride [[CH3(CH2)5]P(Cl)(CH2)13CH3] ionic fluid mixed with organic coconut oil (OCO) during turning of hardened D2 steel. The application of cutting fluid on the cutting interface was performed through Minimum Quantity Lubrication (MQL) approach keeping an eye on the detrimental consequences of conventional flood cooling. PVD coated (TiN/TiCN/TiN) cermet tool was employed in the current experimental work. Taguchi’s L9 orthogonal array and TOPSIS are executed to analysis the influences, significance and optimum parameter settings for predefined process parameters. The prime objective of the current work is to analyze the influence of OCO based Trihexyltetradecylphosphonium Chloride ionic fluid on flank wear, surface roughness, material removal rate, and chip morphology. Better quality of finish (Ra = 0.2 to 1.82 µm) was found with 1% weight fraction but it is not sufficient to control the wear growth. Abrasion, chipping, groove wear, and catastrophic tool tip breakage are recognized as foremost tool failure mechanisms. The significance of responses have been studied with the help of probability plots, main effect plots, contour plots, and surface plots and the correlation between the input and output parameters have been analyzed using regression model. Feed rate and depth of cut are equally influenced (48.98%) the surface finish while cutting speed attributed the strongest influence (90.1%). The material removal rate is strongly prejudiced by cutting speed (69.39 %) followed by feed rate (28.94%) whereas chip reduction coefficient is strongly influenced through the depth of cut (63.4%) succeeded by feed (28.8%). TOPSIS significantly optimized the responses with 67.1 % gain in closeness coefficient.


2020 ◽  
Vol 38 (9A) ◽  
pp. 1406-1413
Author(s):  
Yousif Q. Laibia ◽  
Saad K. Shather

Electrical discharge machining (EDM) is one of the most common non-traditional processes for the manufacture of high precision parts and complex shapes. The EDM process depends on the heat energy between the work material and the tool electrode. This study focused on the material removal rate (MRR), the surface roughness, and tool wear in a 304 stainless steel EDM. The composite electrode consisted of copper (Cu) and silicon carbide (SiC). The current effects imposed on the working material, as well as the pulses that change over time during the experiment. When the current used is (8, 5, 3, 2, 1.5) A, the pulse time used is (12, 25) μs and the size of the space used is (1) mm. Optimum surface roughness under a current of 1.5 A and the pulse time of 25 μs with a maximum MRR of 8 A and the pulse duration of 25 μs.


2020 ◽  
Vol 38 (9A) ◽  
pp. 1352-1358
Author(s):  
Saad K. Shather ◽  
Abbas A. Ibrahim ◽  
Zainab H. Mohsein ◽  
Omar H. Hassoon

Discharge Machining is a non-traditional machining technique and usually applied for hard metals and complex shapes that difficult to machining in the traditional cutting process. This process depends on different parameters that can affect the material removal rate and surface roughness. The electrode material is one of the important parameters in Electro –Discharge Machining (EDM). In this paper, the experimental work carried out by using a composite material electrode and the workpiece material from a high-speed steel plate. The cutting conditions: current (10 Amps, 12 Amps, 14 Amps), pulse on time (100 µs, 150 µs, 200 µs), pulse off time 25 µs, casting technique has been carried out to prepare the composite electrodes copper-sliver. The experimental results showed that Copper-Sliver (weight ratio70:30) gives better results than commonly electrode copper, Material Removal Rate (MRR) Copper-Sliver composite electrode reach to 0.225 gm/min higher than the pure Copper electrode. The lower value of the tool wear rate achieved with the composite electrode is 0.0001 gm/min. The surface roughness of the workpiece improved with a composite electrode compared with the pure electrode.


2020 ◽  
Vol 38 (10A) ◽  
pp. 1489-1503
Author(s):  
Marwa Q. Ibraheem

In this present work use a genetic algorithm for the selection of cutting conditions in milling operation such as cutting speed, feed and depth of cut to investigate the optimal value and the effects of it on the material removal rate and tool wear. The material selected for this work was Ti-6Al-4V Alloy using H13A carbide as a cutting tool. Two objective functions have been adopted gives minimum tool wear and maximum material removal rate that is simultaneously optimized. Finally, it does conclude from the results that the optimal value of cutting speed is (1992.601m/min), depth of cut is (1.55mm) and feed is (148.203mm/rev) for the present work.


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