Figure 2 - uploaded by Xiaohong Lu
Content may be subject to copyright.
Source publication
Due to its superior properties, nickel-based superalloy Inconel 718 can meet the requirements of micro parts with the high strength at high temperatures which have three-dimensional geometry structure like stepped surface, deep-hole, thin wall and so on. However, Inconel 718 is difficult to cut. Now, there are few researches on the cutting forces i...
Context in source publication
Context 1
... ranges of these parameters are shown in Table 1. Micro-milling grooving experiment is the standard orthogonal experiment table L 25 (5 4 ), as shown in Table 2. Table 1 The ranges of these parameters in the micro-milling grooving experiment Image about chip morphology with the mount of micro-milling cutter overhanging L = 12 mm; spindle speed n = 39,680 r/min; axial depth of cut a p = 15 μm; feed per tooth f z = 3.0 μm/z is shown in Figure 2 and long strip chip are obtained. The processing length of groove is 30 mm with dry cutting and air-cooler during experimental processing. ...
Similar publications
Micro-milling tool breakage has become a bottleneck for the development of micro-milling technology. A new method to predict micro-milling tool breakage based on theoretical model is presented in this paper. Based on the previously built micro-milling force model, the bending stress of the micro-milling cutter caused by the distributed load along t...
Citations
... The surface quality is affected by tool wear brought on by a machining operation, as already mentioned above. One of the most important elements in surface finish is the tool's cutting edge radius [42]. It is preferable to micro-mill on the smallest chips in order to create good surface roughness because doing so minimizes surface distortion and therefore enhances surface clarity. ...
The current work was undertaken with the research aim of experimental examination of tool wear, surface roughness and burr formation during the micro-milling of Inconel 718 using different coated tools. Inconel 718 is one of the most widely used materials for purpose-oriented utilization owing to its preferred mechanical and physical properties, including high strength and corrosion resistance. On the opposite end, the machining of Inconel 718 poses certain machinability challenges, which significantly elevates tool wear and subsequently surface roughness. Cutting speed, feed rate and depth of cut were selected as variable machining inputs. With reference to tool wear, all input variables were found to be significant, with tool coating having the highest contribution ratio of 36.19%. In case of surface roughness, cutting speed and tool coating were identified as effective input parameters with contribution ratios of 51.24% and 34.27%, respectively. Similarly, depth of cut proved to be an influential factor for burr height formation (in both up-milling and down-milling), whereas feed rate had the highest contribution ratios for burr width formation during up-milling and down-milling, i.e., 39.28% and 36.26%, respectively. Consequently, contour plots for output responses were drawn between significant parameters to analyze machinability. One of the vital research outcomes was the identification of a tool coating parameter that is significant for all four analyzed aspects of burr formation. In addition, regression equations were formulated for machining responses. The best- and worst-case scenarios for individual input parameters, as identified from main effects plots, were validated during confirmatory experimentation. Moreover, effects of input variables on output response were characterized using close-up imagery, and dominant wear mechanisms were also identified. The utility of the research is underlined by the optimization of the sustainability and productivity of the manufacturing process.
... Increasing the feed rate from 0.5 to 0.1 µ m/tooth resulted in increased surface roughness as demonstrated in Figure 4. In terms of surface finish, the tool's cutting-edge radius is one of the most critical factors [50]. As cutting speed increases, the temperature rises, which in turn affects the roughness of the surface [51]. ...
This research investigates the machinability of Inconel 718 under conventional machining speeds using three different tool coatings in comparison with uncoated tool during milling operation. Cutting speed, feed rate and depth of cut were selected as variable machining parameters to analyze output responses including surface roughness, burr formation and tool wear. It was found that uncoated and AlTiN coated tools resulted in lower tool wear than nACo and TiSiN coated tools. On the other hand, TiSiN coated tools resulted in highest surface roughness and burr formation. Among the three machining parameters, feed was identified as the most influential parameter affecting burr formation. Grey relational analysis identified the most optimal experimental run with a speed of 14 m/min, feed of 1 μm/tooth, and depth of cut of 70 μm using an AlTiN coated tool. ANOVA of the regression model identified the tool coating parameter as most effective, with a contribution ratio of 41.64%, whereas cutting speed and depth of cut were found to have contribution ratios of 18.82% and 8.10%, respectively. Experimental run at response surface optimized conditions resulted in reduced surface roughness and tool wear by 18% and 20%, respectively.
... Xiaohong Lu et al. [59] found that with the increase in the overhanging length of the micromilling cutter and depth of cut, the fluctuation in the cutting forces increases. The cutting forces first increase and then decrease with an increase in cutting speed and feed rate. ...
... From the literature, it can be seen that many researchers used different types of tool coatings in order to increase the tool life and compatibility with different materials during micromilling processes, but a different tool coating was not investigated in order to observe its effect on machining quality by neglecting tool wear. Most of the past studies were carried out using high cutting speeds because of less tool vibration and low burr formation at high cutting speed, while only a handful of studies investigated the quality of micromachined parts at low cutting speeds [45,48,59,64,70]. A low-speed machining setup is readily available and more economical as compared to a high-speed machining setup. ...
Surface roughness and burr formation are among the most important surface quality metrics which determine the quality of the fabricated parts. High precision machined microparts with complex features require micromachining process to achieve the desired yet stringent surface finish and dimensional accuracy. In this research, the effect of cutting speed (m/min), feed rate (µm/tooth), depth of cut (µm) and three types of tool coating (AlTiN, nACo and TiSiN) were analyzed to study their effect on surface roughness and burr formation during the micromachining of Inconel 718. The analysis was carried out using an optical profilometer, scanning electron microscope and statistical technique. Machining tests were performed at low speed with a feed rate (µm/tooth) below the cutting-edge radius for 10 mm cutting length using a carbide tool of 0.5 mm diameter on a CNC milling machine. From this research, it was determined that the depth of cut was the main factor affecting burr formation, while cutting velocity was the main factor affecting the surface roughness. In addition, cutting tool coating did not significantly affect either surface roughness or burr formation due to the difference in coefficient of friction. The types of burr formed during micromilling of Inconel 718 were mainly influenced by the depth of cut and feed rate (µm/tooth) and were not affected by the cutting velocity. It was also concluded that the results for the surface finish at low-speed machining are comparable to that of transition and high-speed machining, while the burr width found during confirmation experiments at low-speed machining was also within an acceptable range.
... The change of mechanical properties causes the change of cutting forces. Therefore, micro-milling is a typical thermal-mechanical coupling process (Lu et al., 2016;Lu et al., 2017). Cutting temperature affects micro-milling cutter seriously because micro-milling tool wear is more sensitive to temperature (Yang et al., 2011). ...
... The change of mechanical properties causes the change of cutting forces. Therefore, micro-milling is a typical thermal-mechanical coupling process (Lu et al., 2016;Lu et al., 2017). Cutting temperature affects micro-milling cutter seriously because micro-milling tool wear is more sensitive to temperature (Yang et al., 2011). ...
Inconel 718 is a kind of typical difficult-to-machine material. Micro-milling technology is an effective method for fabricating micro parts of Inconel 718. The change rules of micro-milling temperature differ from those of the traditional processing, which will affect the surface integrity of the workpiece and the tool life of the micro-milling cutter in different ways. To ascertain the effects of cutting parameters on cutting temperature during micro-milling Inconel 718 and achieve the prediction of cutting temperature, some micro-milling experiments are conducted based on the response surface method. The independent and interaction effects of the spindle speed, feed per tooth and axial cutting depth on cutting temperature are investigated. A micro-milling temperature prediction model is established based on the experiment results. The maximum prediction error is 5.3% and the average prediction error is 2.6%. Finally, the accuracy of the proposed model is validated through experiments of micro-milling Inconel 718.
Nickel-based alloys are widely used in the aerospace industry, nuclear reactors and the automotive industry. These alloys exhibit excellent physical and chemical properties at high temperatures. However, nickel-based alloys are difficult to machine materials with high hardness and low thermal conductivity, which results in high cutting forces during machining. Additionally, increasing demand for meso-scale components in the industry has opened a door for research in this field. This paper focuses on meso-scale milling of Inconel 718 alloy. Aiming at the problem of high cutting forces, meso-scale milling experiments of Inconel 718 alloy were conducted. Due to its high strength and work-hardening characteristics, proper tool coating and process parameters should be selected. In this work, TiAlN, TiSiN, and nACo coatings were selected. Taguchi’s L9 orthogonal array was employed for conducting experiments in a dry environment. In this paper, feed per tooth, cutting velocity, depth of cut, and tool coatings are considered as input parameters, and their effects on cutting forces are analysed through the statistical technique of analysis of variance (ANOVA) to figure out the most important process parameters.
The relative vibration between the micro-milling cutter and workpiece influences the processing quality and tool life. To solve the difficult problem of measurement of vibration displacement between cutting tool and workpiece during micro-milling process, we designed a laser displacement sensor holder, which realizes the adjustment on multi degrees of freedom. A set of vibration displacement measurement system is developed, which utilizes laser displacement sensor to collect vibration signal during micro-milling process. The frequency of micro-milling force is obtained by using varying cutting parameters method. The relationship between cutting force amplitude, frequency and vibration displacement is ascertained by using neural network method to realize vibration displacement prediction under given cutting parameters. The research lays the foundation for vibration suppression of micro-milling, which can help improve surface quality and extend tool life.
