Papers by Keyword: Drilling Force

Abstract: In deep hole machining, drilling parameters for twist drills have an important impact on tool life and economic efficiency. In order to explore the influence of drilling parameters on twist drills, this paper established a drilling model for twist drill 45 steel, orthogonal experiments were designed. AdvantEdge FEM finite element software was used to simulate the drilling force, torque and drilling temperature. The drilling force, torque and drilling temperature were analyzed by using the finite element simulation value as the orthogonal experimental value. In order to ensure that the simulation results have certain reference value, the drilling experiment was carried out in order to ensure the simulation results have reference value. Finally, the optimal combination of drilling parameters was obtained.

Abstract: Cutting force is one of the most important parameters in the machining process, it significantly influenced machining precision of the workpiece, power consumed in the machining process, wear of the cutting tools and so on. There are many factors that affect the cutting force, such as the performance of the workpiece material, cutting speed, usage of the cutting fluid, etc. Single factor variable method was used in this paper, RuT450 was used as workpiece, welded cemented carbide gun drill was used as cutting force and LS-DYNA was used as simulation platform to established the cutting simulation model to analyzed the impact of the cutting speed and feed rate to the drilling force. Simulation results show that, at the low speed drilling stage, drilling force increases with the increase of the feed rate and decreases with the increase of the rotation feed, from the stress cloud it could be seen that the equivalent stress near the drill tip reached the maximum in the drilling process.

Abstract: The application of Ni-based powder metallurgy superalloys materials was limited for its' difficult-to-machine, such as excessive tool wear, frequent tool change, short tool life, low productivity, and large amount of power consumption etc. So the studying of Ni-based powder metallurgy superalloys drilling process becomes extremely important. This paper mainly introduces the research status of drilling of Ni-based powder metallurgy superalloys materials and through synthesize considering cutting force and cost effective, we determined the optimal of cutting tool materials is carbide YG8 twist drill. The optimal parameters of drilling of Ni-based powder metallurgy superalloys: cutting speed of 15m/min, feed per tooth of 0.02mm/r. When the superalloys material is machined by standard twist drill, it is always appearing the failure modes of drilling.

Abstract: Composite materials are used extensively because of their higher strength to weight ratios and, when compared to metals, offer new opportunities for design. However, being non-homogenous, anisotropic and reinforced with very abrasive fibers, these materials are difficult to machine. In this current article is present a comparative study of results obtained in determining the drilling force regression at drilling a tree types composites material with polymeric matrix and fiber glass.

Abstract: This paper explores the drilling characteristics of GH3039 supper alloy. The machining of GH3039 is a difficulty which is commonly used in aircraft and engineer components of the aerospace industry. The spindle speed and feed per tooth are the major influence factors which are studied to gain large removal rate and predict the drilling characteristics. So the single factor test is carried out about spindle speed and feed per tooth. The results of the experiment show that the drilling force of GH3039 decreased with the increasing of spindle speed up to 900r/min which is larger than other metal drilling process. The small feed per tooth may obtain small drilling force. So too low spindle speed and large feed per tooth are not adopted in the GH3039 drilling process. The analysis of the chip formation also verifies the above characteristics. At the same time, the serious serrated chip is occurred which is adverse for the drilling. It has significant for other supper alloy real drilling process.

Abstract: The new developed carbon fiber reinforced polymer laminates are widely used in main structural components of big commercial aircrafts. Generally drilling is the final operations in manufacturing structure, which is the most important operation during assembly. Defects such as burrs and delamination always appear in the process of drilling, which makes it hard to control the drilling quality. In this research, the drilling defects of T800 CFRP laminates are evaluated by using a brad point drill and a multifacet drill in terms of drilling forces, burr defect and delamination detection. The results show that the spindle speed is the most significant factor affecting the delamination defect followed by the feed rate. High speed drilling and low feed rate could improve the surface quality and reduce the delamination. The multifacet drill showed excellent drilling performance than the brad point drill and generated smaller defects.

Abstract: Stainless steel is difficult to machine, especially micro-hole machining. In order to obtain the effect of drilling force by tool material and cutting parameters, the drilling experiments on stainless steel 1Cr18Ni9Ti have been done by diameter of 1.2 mm containing cobalt high speed steel and carbide drill. According to the experimental results, analysising the reason of drilling force change under different parameters and establishing a carbide drill drilling force empirical formula which combined with the regression analysis method.

Abstract: Composite materials are used extensively because of their higher strength to weight ratios and, when compared to metals, offer new opportunities for design. However, being non-homogenous, anisotropic and reinforced with very abrasive fibers, these materials are difficult to machine. In this current article is present a comparative study of results obtained in determining the drilling force regression at drilling a tree types composites material with polymeric matrix and fiber glass.

Abstract: The changes of drilling forces during bone drilling provide a useful index for evaluating the risk of potential damage to the bone. The aim of the work is that an elastic-plastic dynamic finite element model is used to simulate the process of a drill bit drilling through the bone. The finite element model was set up in the Abaqus6.11; the prediction model of the drilling force was gotten by using the regression orthogonal experiment and data processing software Matlab7.0. Diverse values of drilling speed, feed rate and drill diameter are important factors which will lead to changes in the drilling forces. By controlling the drilling parameters can obtain the optimal drilling force. The results show that the diameter has the greatest influence on the drilling force, the drilling speed the second, the feed rate the last.

Abstract: In this paper, the authors built the test device for CFRP drilling machining and drilling force detection system. An experimental research was conducted on the drilling force of CFRP drilling. Based on the multiple liner regression analysis through SPSS software, the empirical formula, considering the spindle speed and feed rate, is presented for predicting the drilling force. The results obtained were satisfactorily validated by comparing the experimental findings with the corresponding theoretical data and it is possible to conclude that the model affords a focused approach to the definition of the most appropriate drill geometry and cutting parameters in composite materials drilling.