Papers by Keyword: Drilling

Abstract: The continuous demand focused on optimizing titanium machining techniques in the aerospace industry, makes improving machining processes in this area of great interest to the industry. The contamination produced by the coolants used to machine titanium is a major problem to be addressed, since it is a material that requires cooling due to its strength, physical qualities and low thermal conductivity. That is why the implementation of a RHVT cooling system can improve the current situation. The aim of this work is to compare the final quality of the drilling by applying the system of RHTV (Ranque Hilsch Vortex Tube) cooling techniques and to see the advantages of its application with the dry machining process. This cooling system is expected to reduce drilling temperatures, thereby increasing the environmental performance of the manufacturing process. It is expected to set up a preliminary study based on a comparison between dry drilling and drilling assisted by the application of RHTV. Macro and microgeometric defects will be evaluated to determine the cooling system efficiency, as well as the machining temperatures reached.

Abstract: The present work aims to understand the effect of drilling parameters (drill speed and feed rate) during the drilling of saffil fiber-reinforced Al metal matrix composite (MMC) under dry conditions. The effect of drilling parameters on individual response characteristics is evaluated and the optimum drilling parameters are also investigated using a multi-response optimization technique known as Entropy Weighted Grey Relational Analysis (EWGRA). The drilling parameter optimization has been performed with aim of minimizing the surface roughness of drilled hole, roundness error in drilled hole and feed force during drilling. Weights were assigned to individual responses with the Entropy weight method and Grey relational grades were calculated to obtain the optimal level for drilling parameters. To achieve the minimum values for all output responses the optimal value of drill speed is 22 m/min and the feed rate is 0.075 mm/rev.

Abstract: Composite with woven ramie as reinforcement is a combination of woven from hemp plant fibers with resin adhesive (matrix) which each has different characteristics, which with the combination will produce a new material with better properties. The purpose of this study is to determine the magnitude of the influence of federate variations on the tensile strength of open holes in drilling, with the test method carried out with reference to ASTM D 5766/D 5766M-02 (Standard Test Method for Open Hole Tensile Strength of Polymer Matrix Composite Laminates). The tensile test speed used is 5 mm/minute. The data taken is the maximum tensile strength when the specimen breaks. The results of this study indicate that the change in feed rate affects the tensile strength of the ramie composite. The greater the feed rate used is in grading the ramie fiber composite, the smaller the composite tensile stress value becomes. In this study, the highest tensile strength is obtained from composites with a feed rate of 0.05 mm/rev and the lowest at a feed rate of 0.15 mm/rev. The change in spindle speed also affects the magnitude of the tensile strength in the ramie composite. As with the feed rate speed, the greater the spindle speed used to grind the composite, the lower the tensile strength of the composite. In this study, the maximum tensile strength value tends to be obtained by a composite with a spindle speed of 88 rpm and the lowest at a spindle speed of 1500 rpm. This study uses the type of chisel "brad and spur" with three kinds of diameter variations. The larger the diameter of the drill chisel used, the smaller the tensile strength of the composite obtained.

Abstract: The aim of this research work is identification of optimum drilling parameters to increase material removal rate, dimensional and profile accuracy during drilling. ASTM A516 (Grade70) which is a boiler quality plate of 12 mm thickness was considered as the specimen for conducting the experiments. The experiment was done based on full factorial design using 18 experiments generated using Minitab Software. Two levels for tool material and three levels for feed-speed combination and cutting environment were considered. Two runs were carried out for each trial. The metal removal rate was calculated for each hole drilled. The mean result of the two runs of a trial was taken as the result of the trial. The drilled holes were then tested for their dimensional, profile accuracies. With these results in hand the Artificial Neural Network software was trained to predict the optimized input parameters for drilling a hole of required dimensional and profile accuracies and with required metal removal rate.

Abstract: This titanium material is very difficult to machine due to its low thermal conductivity resulting in heat generated when machining accumulates in the cutting zone. This causes the thermal effect to be absorbed in the drill tool so that the tool wears out quickly which affects the quality of the hole. This study aims to examine the effect of tool wear on the cutting force of hole quality under dry machining conditions and machining using the MQL method. The cutting force resulting from the process of drilling holes using MQL is smaller than drilling in dry conditions. The larger the feed (f), the greater the cutting force (N) that is generated during the drilling process in dry conditions and MQL conditions. The greater the cutting speed (v) used during the drilling process, the lower the cutting force generated

Abstract: The demand for lighter and more performant aerospace and automotive components has resulted in a substantial surge in a recent interest in parts made of Fiber Metal Laminates (FMLs). For such components, drilling operations are crucial for permitting subsequent assembly. However, drillability of fiber metal laminates is critical due to the heterogeneous thermal and mechanical properties of the metal and composite that form the laminate. In this framework, the current research work aims at understanding how drilling operations can be affected by different surface treatments carried out on AZ31B magnesium alloy sheets joined with Glass Fiber Reinforced Polyamide 6 (PA6-GFRP) via hot metal pressing to form the FML. To this end, the Mg/PA6-GFRP/Mg composites were first fabricated using AZ31B surfaces that were previously treated through sandblasting, annealing, and their combination. Dry drilling was then performed using twist and spur drill bits. The feed was also varied, using two levels. The thrust force, hole quality, delamination and fiber pull-out were considered to evaluate the FMLs drillability. Results showed that the magnesium alloy sheet treatment influenced the drillability, and that the drill bit had an effect too. In particular, sheets that were both sandblasted and annealed allowed the highest drillability avoiding delamination. The use of spur drill bits improved the drillability too, reducing the FML inflection under the drill bit load.

Abstract: Known technological solutions for well drilling waste utilization are analyzed. The technological decision of the device of storage of drilling waste from soil-cement elements with the device of a covering from soil-cement is offered. It is proposed to fill the repository with waste in layers of drilling mud, site soil, using a layer of composition for neutralization with the use of ash burning wood residues. The composition is proposed to be prepared near storage facilities. It is proposed to make the neutralizing composition periodically in the sludge storage as they are filled. In the case of a high level of sludge contamination with petroleum products, sorbents are added in addition to filling the storage. The thickness of the layers is chosen based on optimal humidity. It is offered to add ash from the Mykolayiv thermal power plant in the amount of 5 wt.% By weight of cement when installing the walls and covering the sludge storage from soil cement. It was found that with increasing the shelf life of samples in water to 270 days increases the average compressive strength of soil cement samples without additives and with the addition of the appropriate percentage of fly ash by more than 7%.

Abstract: The article deals with the methods of forming liquid rocket engines parts, in which sheet material is used as a blank. The analysis of the existing methods of processing workpieces with a variable surface profile allows us to conclude that the mechanical method is the most promising type of processing for hole perforation. The drilling holes technology in parts made of sheet blanks is presented. The features of processing non-rigid parts with unpredictable surface fluctuations are considered. The ways of ensuring the stability of the treatment process, increasing the technological indicators, which allowed expanding the area of dimensional machining, are shown. The results of the work contribute to improving the manufacturability of new generations products of equipment, which is important for mechanical engineering.

Abstract: The authors of the article analyze the known technological solutions for the disposal of waste from drilling wells. The authors propose a technological solution for the arrangement of drilling waste storage from soil-cement elements with the installation of soil-cement coating. Filling the storage facility with waste is proposed to be carried out with layers of drilling mud, soil, ash. Used a layer of fly ash to reduce humidity, if it differs from the optimum. The thickness of the layers was chosen based on ensuring optimal humidity. The authors propose to add ash from the Mykolayiv thermal power plant in the amount of 5 wt.% By weight of cement when installing the walls and covering the sludge storage from soil cement. It is established that with increasing the shelf life of samples in water up to 180 days, the average compressive strength of soil cement samples increases. If we compare without additives and with the addition of the appropriate percentage of removal ash, the value of strength increases by 12-15%.

Abstract: The paper presents the results of numerical experimental studies of cutting titanium blanks using mathematical modeling programs, which make it possible to completely repeat technological processes in a computer (digital twin). The LS-DYNA product was used as a program to simulate the process of stock removal from titanium blank. It has been established that the use of this method adequately describes the cutting processes, including with the introduction of the energy of an ultrasonic field into the processing zone, can significantly reduce the duration of experimental research and evaluate the influence of the elements of the cutting mode and design parameters of the tool on the thermal power aspects of the formation of new surfaces of machine parts.