The Optimal Process Analysis for Precision-Drilling of Mold Steel SKD61

2007 ◽  
Vol 364-366 ◽  
pp. 649-654
Author(s):  
Wann Yih Lin ◽  
Bean Yin Lee

The Taguchi method is regarded as a powerful tool to design optimization for quality. In this study, it was used to find the optimal cutting parameters for precision-drilling operations. The cutting parameters include guiding drilling, spindle speed, feed rate, stepping amount, number of steps and cutting fluid. The considered characteristics of performance are tool life, and the variation of drilled hole-diameter. Taguchi Method and Orthogonal Array were applied to the experiments of precision-drilling so as to allocate the corresponding processing parameters. The obtained results were then evaluated by Response Table, Response Chart, and Analysis of Variance methods (ANOVA) to acquire the optimal processing parameters. These were further confirmed by experiment. Finally, the analysis of the precision-drilling process applied for mold steel SKD61 shows that this approach can greatly improve the drilling performance of a small-drilling process.

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Qiang Fang ◽  
Ze-Min Pan ◽  
Bing Han ◽  
Shao-Hua Fei ◽  
Guan-Hua Xu ◽  
...  

Drilling carbon fiber reinforced plastics and titanium (CFRP/Ti) stacks is one of the most important activities in aircraft assembly. It is favorable to use different drilling parameters for each layer due to their dissimilar machining properties. However, large aircraft parts with changing profiles lead to variation of thickness along the profiles, which makes it challenging to adapt the cutting parameters for different materials being drilled. This paper proposes a force sensorless method based on cutting force observer for monitoring the thrust force and identifying the drilling material during the drilling process. The cutting force observer, which is the combination of an adaptive disturbance observer and friction force model, is used to estimate the thrust force. An in-process algorithm is developed to monitor the variation of the thrust force for detecting the stack interface between the CFRP and titanium materials. Robotic orbital drilling experiments have been conducted on CFRP/Ti stacks. The estimate error of the cutting force observer was less than 13%, and the stack interface was detected in 0.25 s (or 0.05 mm) before or after the tool transited it. The results show that the proposed method can successfully detect the CFRP/Ti stack interface for the cutting parameters adaptation.


Author(s):  
Daiyan Ahmed ◽  
Yingjian Xiao ◽  
Jeronimo de Moura ◽  
Stephen D. Butt

Abstract Optimum production from vein-type deposits requires the Narrow Vein Mining (NVM) process where excavation is accomplished by drilling larger diameter holes. To drill into the veins to successfully extract the ore deposits, a conventional rotary drilling rig is mounted on the ground. These operations are generally conducted by drilling a pilot hole in a narrow vein followed by a hole widening operation. Initially, a pilot hole is drilled for exploration purposes, to guide the larger diameter hole and to control the trajectory, and the next step in the excavation is progressed by hole widening operation. Drilling cutting properties, such as particle size distribution, volume, and shape may expose a significant drilling problem or may provide justification for performance enhancement decisions. In this study, a laboratory hole widening drilling process performance was evaluated by drilling cutting analysis. Drill-off Tests (DOT) were conducted in the Drilling Technology Laboratory (DTL) by dint of a Small Drilling Simulator (SDS) to generate the drilling parameters and to collect the cuttings. Different drilling operations were assessed based on Rate of Penetration (ROP), Weight on Bit (WOB), Rotation per Minute (RPM), Mechanical Specific Energy (MSE) and Drilling Efficiency (DE). A conducive schedule for achieving the objectives was developed, in addition to cuttings for further interpretation. A comprehensive study for the hole widening operation was conducted by involving intensive drilling cutting analysis, drilling parameters, and drilling performance leading to recommendations for full-scale drilling operations.


2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Chi-Ting Lee ◽  
Soham S. Mujumdar ◽  
Shiv G. Kapoor

In drilling, chip-clogging results in increased drilling temperature, excessive tool wear, and poor hole quality. Especially, in microdrilling, low rigidity of the tool and inability of cutting fluid to penetrate narrower tool–workpiece interface significantly reduce the drilling performance. A novel bubble-mixed cutting fluid delivery method proposed in this research aims toward achieving a high-performance micro deep-hole drilling process with a significant reduction in the consumption of cutting fluid. Experimental results show that the bubble-mixed cutting fluid delivery method achieves lower thrust force during drilling, higher drilled depth before tool breakage, and lower dimensional and circularity errors when machining deep holes in comparison with dry cutting or conventional flood delivery method. It is also found that the smaller-sized bubbles effectively penetrate the tool–workpiece interface during the drilling producing deeper holes by better chip evacuation and cooling.


2008 ◽  
Vol 381-382 ◽  
pp. 225-228 ◽  
Author(s):  
Gyula Varga ◽  
Illes Dudas

Nowadays more and more scientific papers deal with drilling. The drilling process has been used for more than 5000 years and the development of conventional drills is more than 200 years old. In recent years there have been limited changes to the drill design but considerable improvements have been made in the selection of drill materials, drill coatings, flute design and cutting fluid guiding methods. The paper briefly describes the development of surface characterisation including its current 3D capability. It shows how selected parameters can assist with drill process analysis and how this can be supported through the introduction of the planned new ISO International Standard for 3D Surface characterisation. The paper is supported by a sample drilling test to demonstrate the power of the proposed analysis.


2020 ◽  
Vol 177 ◽  
pp. 01008
Author(s):  
Andrey Regotunov ◽  
Rudolf Sukhov ◽  
Gennady Bersenyov

As a system, the mining enterprise develops under constantly changing conditions of the external and internal environment. These conditions affect the state of the most important drilling subsystem: blasthole drilling technology, safety, performance, power consumption of the boring rigs and roller bits used. The main transition processes as necessary responses of the subsystem to changing conditions were identified as a result of fragmentary data analysis showing decisions taken over the past 15-20 years, which increase drilling activity efficiency and safety of smaller quarries of Russia, which contain a significant amount of material resources. The main transition processes contribute to the growth of drilling performance and consist of changing the following: bit design for specific rocks; drilling method; drilling mode; boring rig design; controlled parameters of drilling process and rock properties redetermination; parameters of maintenance and repair system. Based on the performed analysis, the systematization results of the main factors predetermining the need for transition processes implementation in the “drilling operations” subsystem were obtained and presented. The proposed approach allowed to reveal a holistic picture of the main interacting factors in the “drilling operations” subsystem. Based on the factors systematization presented in the article it is possible to envisage changes of individual factors depending on changes of other factors, not functionally related directly when planning drilling operations.


2012 ◽  
Vol 723 ◽  
pp. 196-201 ◽  
Author(s):  
Peng Nan Li ◽  
Ming Chen ◽  
Xiao Jian Kang ◽  
Li Na Zhang ◽  
Ming Zhou

In this study AISI 1045 steel of different hardness are used in high speed milling. According to Taguchi method, cutting parameters (milling speed, milling depth, feed per tooth) and workpiece hardness for the influence of high speed milling of the surface roughness are optimized. Through this study, not only the optimal cutting parameters of the minimum surface roughness is obtained, but also the main cutting parameters that effect performance in high speed milling is analysed. Researching results can be provided to guide establishment of the high speed milling process.


2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Chung-Feng Jeffrey Kuo ◽  
Hui-Ta Chen ◽  
Te-Li Su ◽  
Jr-Da Huang

Flip-chip bonding is a kind of chip packaging technology, which can make fabricated chips lighter and smaller. Thermo-ultrasonic flip-chip bonding is a technology that directly joins gold pad and gold bump. This study combines principle component analysis and gray relational analysis to determine the optimal processing parameters for multiple quality characteristics of light emitting diodes (LEDs). The quality characteristics of this experiment include the candle light, forward voltage, and leakage current of LED and thrust value. First, this study determines the processing parameters that may affect the thermo-ultrasonic flip-chip bonding with the L18 orthogonal array, including substrate temperature, bonding downforce, ultrasonic working time, ultrasonic power, and rising and delay time of tool head bonding. Then, the gray relational analysis is applied to indicate the optimal processing parameters for the multiple quality characteristics of LED. Since the Taguchi method only takes one single quality characteristic into consideration, this study applies the Taguchi method to reduce the number of thermo-ultrasonic flip-chip bonding experiments. The experimental results prove that the optimal LED has good integral quality, which is above industrial standard.


2006 ◽  
Vol 505-507 ◽  
pp. 823-828 ◽  
Author(s):  
Yu Chieh Chen ◽  
Yunn Shiuan Liao ◽  
J.D. Fan

This paper presents an optimal cutting-parameter design of heavy cutting in side milling for SUS304 stainless steel. The orthogonal array with relational analysis is applied to optimize the side milling process with multiple performance characteristics. A grey relational grade obtained from the grey relational analysis is used as a performance index to determine the optimal cutting parameters. The selected cutting parameters are cutting speed, feed per tooth, axial depth of cut, and radial depth of cut, while the considered performance characteristics are tool life and metal removal rate. Experimental results have shown that cutting performance in the side milling process for heavy cutting can be significantly improved through this approach.


2012 ◽  
Vol 233 ◽  
pp. 343-346
Author(s):  
Wen Hui Cao ◽  
Hong Bin Liu ◽  
Shen Song Wang ◽  
Ting Yang

The optimization of the parameters in high-speed milling was analyzed based on the principal component analysis and the Taguchi method. The cutting speed, feed per tooth and cutting depth were selected as the cutting parameters while the cutting force, cutting power and surface roughness parameters were selected as quality characteristics. The optimum cutting parameters were obtained and the comprehensive quality of high - speed hard machining has been guaranteed.


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