Alloy Drill Research Articles

Study on Interface Behavior of SiC/SiO2/Al and SiC/Ni/Al

High-temperature oxidation and electroless nickel plating are two common surface modification processes to improve the wettability of SiC/Al interface. The structure and properties of SiC/SiO2/Al and SiC/Ni/Al interface layers were studied for the preparation of aluminum alloy drill pipe. Two kinds of 6.5%SiC/Al–Cu–Mg–Zn composite ingot were prepared using vacuum melting/casting method, and the added SiC particles in the composites were modified by high-temperature oxidation and electroless nickel plating, respectively. Analysis of structure demonstrates that the interface structures of composites ingot are SiC/SiO2/Al structure and SiC/Ni/Al structure, respectively. For SiC/SiO2/Al interface structure, a smooth and dense SiO2 film is well bonded to SiC and Al by chemical bonding. For SiC/Ni/Al interface structure, there is a very thin Ni film between SiC and Al and the bonding strength between Ni and Al is not so strong. Results of the performance test of the composites indicate that the tensile strength and compressive strength of the composites with SiC/SiO2/Al interface structure, respectively, increase by 7.51% and 24.90%, compared with the composites ingot with SiC/Ni/Al interface structure.

Scanning Electron Microscopy Analysis and Energy Dispersion X-ray Microanalysis to Evaluate the Effects of Decontamination Chemicals and Heat Sterilization on Implant Surgical Drills: Zirconia vs. Steel

Background: Drills are an indispensable tool for dental implant surgery. Today, there are ceramic zirconium dioxide and metal alloy drills available. Osteotomy drills are critical instruments since they come in contact with blood and saliva. Furthermore, they are reusable and should be cleaned and sterilized between uses. Depending on the material, sterilizing agents and protocols can alter the surface and sharpness of implant drills. The hypothesis is that cleaning and sterilization procedures can affect the surface structure of the drills and consequently reduce their cutting efficiency. Methods: Eighteen zirconia ceramic drills and eighteen metal alloy drills were evaluated. Within the scope of this study, the drills were not used to prepare implant sites. They were immersed for 10 min in human blood taken from volunteer subjects and then separately exposed to 50 cycles of cleansing with 6% hydrogen peroxide, cold sterilization with glutaraldehyde 2%, and autoclave heat sterilization. Scanning Electron Microscopy (SEM) and energy dispersion X-ray (EDX) microanalysis were conducted before and after each cycle and was used to evaluate the drill surfaces for alterations. Results: After exposure to the cleansing agents used in this study, alterations were seen in the steel drills compared to zirconia. Conclusions: The chemical sterilization products used in this study cause corrosion of the metal drills and reduce their sharpness. It was observed that the cycles of steam sterilization did not affect any of the drills. Zirconia drill surfaces remained stable.

Using a supperficially treated 2024 aluminum alloy drill pipe to delay failure during dynamic loading

For many years, a critical factor while drilling deep wells in Algeria oil fields has been the fatigue loads in drill strings used in high tortuosity sections. One solution is the use of drill pipes made of alternative lighter materials instead of conventional steel. A thorough study of superficially (ST) treated 2024 aluminum alloy joined to steel drill pipes in crooked well trajectories is presented in this article. This work discusses several limiting loads exerted on the drill pipes that affect the drilling operation such as axial, twisting and bending forces, which lead to combined cyclic loads. This study is aimed to determine whether it is possible to extend the drilling operation by joining ST 2024 aluminum alloy drill pipes into the drilling string, without losing drilling stability or reliability. It is established that the ST 2024 aluminum alloy drill pipe exerts significant influence on the allowable combined load, but affects to a larger extent the critical load at which loss of drilling string stability occurs, along with improved resistance to wear and corrosion, even at high temperature.

Effects of graphene nanosheets on the ceramic coatings formed on Ti6Al4V alloy drill pipe by plasma electrolytic oxidation

Ceramic coatings were formed on the surface of Ti6Al4V alloy drill pipe by plasma electrolytic oxidation (PEO) technology in the silicate electrolyte with and without graphene nanosheets. Voltage-time responses were recorded. The microstructure, elements distribution and phase composition were investigated by SEM, TEM, EDS and XRD. The basic physical properties and wear resistance were studied. The morphology of wear tracks was observed by SEM and three-dimensional microscope. Results indicated graphene nanosheets successfully incorporated in the ceramic coating. The main elemental components were Ti, Si and O. They were crystallized and composed of anatase and rutile. The coating with graphene nanosheets showing the morphology and structure of flatter and less pores was superior to the coating without graphene nanosheets exhibiting rugged and more pores, and the microhardness of the coating with graphene nanosheets was 1250 HV which was noteworthy improved in contrast with the coating without graphene nanosheets of 870 HV. Wear test results showed the coating with graphene nanosheets displayed extremely significant wear resistance due to the physical barrier of graphene nanosheets. In summary, the application of graphene nanosheets to improve the wear resistance of titanium alloy drill pipe is a promising and promotional research.

A Comparative Study between Regression and Neural Networks for Modeling Al6082-T6 Alloy Drilling

Apart from experimental research, the development of accurate and efficient models is considerably important in the field of manufacturing processes. Initially, regression models were significantly popular for this purpose, but later, the soft computing models were proven as a viable alternative to the established models. However, the effectiveness of soft computing models can be often dependent on the size of the experimental dataset, and it can be lower compared to that of the regression models for a small-sized dataset. In the present study, it is intended to conduct a comparison of the performance of various neural network models, such as the Multi-layer Perceptron (MLP), the Radial Basis Function Neural Network (RBF-NN), and the Adaptive Neuro-Fuzzy Inference System (ANFIS) models with the performance of a multiple regression model. For the development of the models, data from drilling experiments on an Al6082-T6 workpiece for various process conditions are employed, and the performance of models related to thrust force (Fz) and cutting torque (Mz) is assessed based on several criteria. From the analysis, it was found that the MLP models were superior to the other neural networks model and the regression model, as they were able to achieve a relatively lower prediction error for both models of Fz and Mz.

Study on Drilling Parameters Optimization of Aluminum Alloy-Steel Hybrid Drill Pipe

With the increasing number of wells with complex operating conditions, the requirements for oil exploration equipment and technology are higher than ever before. Aluminum alloy drill pipe gradually receives good graces because of its light weight, high strength to mass ratio and strong corrosion resistance. This paper calculates different drillstring combinations according to the same horizontal well. It is found that the hook load and total friction resistance of the aluminum alloy-steel drillstring combination are smallest in the horizontal well, and aluminum alloy-steel drillstring combination is the optimal design. This paper studies the dynamic characteristics of aluminum alloy drill pipe by nonlinear finite element method. The simulation results show that rotation speed has a great influence on the trajectory of the aluminum alloy drill string in the vertical section.When the rotation speed is large, the centrifugal force makes the drill string move close to the wall, and the wear of the drill string is intensified. Besides, The moving range of the rotating drill string in the stable inclined section is close to the lower right part of the wellbore. When the WOB is constant, the range and amplitude of the lateral vibration of the drill string in the X and Y directions become larger as the rotational speed increases.

Research Status and Development of Titanium Alloy Drill Pipes

Petroleum and natural gas exploration and development are deepening, and the environment and stratum conditions encountered are becoming more and more complex. There are many high-temperature, high-pressure, high-corrosion wells, and the number of ultra-short horizontal directional wells, ultra-deep wells, and extended reach wells are also increasing. The steel drill pipe has not been able to meet and adapt to these requirements. Titanium alloy drill pipe has a series of advantages such as low density, high specific strength, excellent corrosion resistance, high temperature resistance, fatigue resistance, non-magnetic and good flexibility. It is suitable for the development of modern petroleum industry. This article discusses the use of titanium alloy drill pipe in domestic and foreign drilling in horizontal wells with short radius, the design of alloy components in titanium alloy drill pipes, body pipe processing, joint connection and corrosion resistance. Combining the practical application of titanium alloy drill pipe points out the current problems. Finally, from the aspect of drilling cycle, production safety and cost saving, the development and application of titanium alloy drill pipes in deep wells, ultra-deep wells and deep-sea drilling operations are prospected.

Improving Corrosion Resistance and Corrosive Wear Resistance of Aluminum Alloy Drill Pipe by Surface Nanocrystallization and Micro-arc Oxidation

To improve the corrosion and wear resistance performance of aluminum alloy drill pipes in geological and petroleum drilling applications, a strengthening coating was prepared on the surface of the 2618 aluminum alloy by combining treatment with ultrasonic cold forging technology (UCFT) and micro-arc oxidation (MAO). The effects of the strengthening coating on the corrosion and wear resistance of the aluminum alloy were evaluated by electrochemical and tribological tests. The results demonstrated that the corrosion and wear resistance of the aluminum alloy were improved by the UCFT and MAO technologies, especially the salt corrosion resistance. The corrosion morphology of the strengthening coating primarily included pitting, micro-cracks and NaCl attachment. In addition, the UCFT + MAO composite coating exhibited the best wear performance. The wear rate of the UCFT + MAO composite coating was lower than that of the aluminum alloy by 94%. The results provided support for this excellent surface treatment technology for the corrosion and wear resistance of aluminum alloy drill pipes, and they also present a feasible evaluation method for drill pipes.

Evaluation of novel tool geometries in dry drilling aluminium 2024-T351/titanium Ti6Al4V stack

Three novel drill geometries, multipoint, step and double cone, were designed and experimentally evaluated to understand the effect of tool geometries on the machining performance of dry drilling Al/Ti stack. Results showed that the double cone drill achieved a better hole quality and a higher efficiency due to the smaller thrust force, broken chips, and less burrs compared to the other two drill geometries. The multipoint drill generated serrated chips in titanium alloy drilling. Significant microstructure deformation occurred in the adiabatic shear band (ASB) and the second shear band. Visible cracks propagated along the ASB from the free to back surface of the chip. Phase transformation from β phase to martensite occurred in the second shear band. The drill geometry design and experimental investigation in this paper could provide guidance for drill bit design and manufacturing for Al/Ti stack drilling.

Effect of Extrusion Texture on Mechanical and Electrochemical Properties of Aluminum Alloy Drill Pipe

Aiming at the special service environment of aluminum alloy drill pipe, in this paper, the influence of extrusion texture on the mechanical and electrochemical properties of aluminum alloy drill pipe was studied. And the macroscopic textures of longitudinal profile and cross section of aluminum alloy drill pipe were tested, and the tensile, compressive and impact mechanical properties were tested, followed by immersion and electrochemical testing. The results show that the texture which 2A12T4 aluminum alloy drill pipe contains is <001> and <111> along the extrusion direction and <223>, <101> in the transverse direction. The test results of mechanical properties show that the extruded texture will affects the mechanical properties of material. When the cross section and longitudinal profile samples of 2A12T4 were soaked in 3.5% NaCl solution at 25°C, 60°C and 90°C, their corrosion resistance are different. The pits of transverse specimens exhibit a dispersed distribution and that of longitudinal specimens are distributed along the extrusion direction.

Numerical simulation of multi-spark electric discharge machining analysis for Ti6Al4V alloy drilling

In this paper a thermal model has been developed for numerically analyzing the multi spark EDM drilling mechanism using finite element methods. The sequential multi electric sparks for drilling process provides heat flux for simulation model. The thermal model also envelopes realistic considerations like effective latent heat of melting, Gaussian heat distribution of heat source, spark radius equation encompassing discharge current and pulse on time, etc for predicting the rate of metal removal and shape of the drilled hole cavity. This developed model has been used to determine the effect of parameters used as input for EDM process like discharge current, voltage, pulse duration and duty cycle on MRR and crater cavity. The impact of discharge energy on MRR is studied and behaviors of crater depth on variance in input operation parameters are examined. The results obtained could be used to carry out experiments and develop an empirical model which could predict results for operation output parameters like MRR, TWR and surface roughness in advance.

Effect of aging processes on corrosion behavior and stress corrosion sensitivity of pre‐stretched 7075 aluminum alloy

In this work, the microstructures, corrosion behavior, and sensitivity to stress corrosion cracking (SCC) of pre‐stretched 7075 aluminum alloy drill pipes with 2.5–3% tensile plastic deformation in a 3.5% sodium chloride solution are studied. The alloy samples are separately subjected to single‐stage aging, two‐stage aging, and three‐stage aging. The polarization curves of the samples all demonstrate passivation characteristics after the different aging treatments. Single‐stage aging of the sample results in poor corrosion resistance and high SCC sensitivity with continuously distributed grain boundaries. After two‐stage aging, the sample exhibits improved corrosion resistance and SCC sensitivity, with intermittently distributed grain boundaries. Three‐stage aging imparts the alloy with remarkable corrosion resistance and significantly reduced SCC sensitivity, with intermittently distributed grain boundaries. Thus, the three‐stage sample is considered to be the best choice for aluminum alloy drill pipes intended for applications involving heat‐treatment.

Experimental study and optimization of cutting parameters in machining of super alloy with hybrid ultrasonic method

Super alloys are intensively used in various industries, especially in the aerospace industry, because of their special characteristics. A number of holes are sometimes required to be drilled into super alloys for aircraft at their final stage assembly. In the present study, a hybrid ultrasonic machining method, called rotary ultrasonic machining (RUM), was successfully used in super alloy drilling. The empirical modeling of the process parameters of RUM was performed for the super alloy (Inconel 718) using an experimental design approach, called response surface methodology (RSM). Parameters, namely tool rotation, feed rate, ultrasonic power, and abrasive grit size, were selected as input variables. The others were kept constant. The performance was measured in terms of the machining rate and the surface roughness. The developed models were found to be reliable representatives of the experimental results with prediction errors less than ±5%. Moreover, the feed rate for the quality and productivity aspect was found to be the most critical factor. The optimized values of the machining rate and the surface roughness achieved through a multi-response optimization were 0.9 825 mm3/s and 0.951 μm, respectively.

Effects of evaluated temperature on tribological behaviors of micro-arc oxidated 2219 aluminum alloy and their field application

The effect of evaluated temperatures on tribological properties of micro-arc oxidated (MAO) 2219 aluminum alloy was investigated. Tribotests were carried out under 25, 80, 120, and 160 °C, and the field drilling test was carried out in “Yang D1 Well”. The results reveal that the friction coefficient of MAO sample decreases with the increase of temperature, the wear rate of MAO sample increases with the increase of temperature, and the load bearing capacity of MAO coating reduces when the temperature goes up. However, comparing with the untreated sample, the wear rate of MAO sample is reduced by 60% at 160 °C. The main wear mechanism of MAO sample is slight abrasive wear under high temperature. The outer loose layer of MAO coating is obviously sheared off under low load and high temperature, resulting in the decrease of friction coefficient. The low loading capacity causes the high wear rate of aluminum alloy at elevated temperature. In the field application, the minimum amount of wear loss is 0.06 mm in the B position of the MAO aluminum alloy drilling pipe.

Inverse solution to heat transfer coefficient during heat assembly of aluminum alloy drill pipes

With the rapid development of oil and gas industry, as well as geological exploration industry, the requirements on properties of aluminum alloy drill pipes are increasing. During heat assembly of aluminum alloy drill pipes, the cooling process inside the pipes has a direct impact on the connection performance of pipes. Thus, study of the convective heat transfer coefficient between the cooling water and the internal wall of aluminum alloy pipes is important. Conventional algorithms cannot easily solve the problem of determining the heat transfer coefficient at the complex structure of aluminum alloy drill pipes. Therefore, this article conducts a heat assembly experiment between aluminum alloy drill pipes and steel joints to obtain adequate, accurate temperature data. Based on these experimental data and an inverse heat conduction model, the heat transfer coefficients during the heat assembly process are determined by a finite element program and the differential evolution algorithm. The correlation curve between the cooling water flowrate and the convective heat transfer coefficient obtained in this article is important in the accurate prediction of heat transfer capacity and temperature field distribution during heat assembly at different cooling water flowrates. The analysis results show that the heat transfer coefficients are nonlinear functions of cooling water flowrates. The temperature is highest at location A1 and gradually declines backward along the axis of the drill pipe. The heat transfer coefficient gradually declines backward along the axis of the drill pipe. The increasing flowrate of cooling water will cause the convective heat transfer coefficient along the axis of the drill pipe to escalate irregularly.

Influence of plasma shock wave on the morphology of laser drilling in different environments

Nanosecond pulse laser was used to study nickel-based alloy drilling and compare processing results of microholes in air environment and water environment. Through analysis and comparison, it's found that environmental medium had obvious influence on morphology of laser drilling. High-speed camera was used to shoot plasma morphology during laser drilling process, theoretical formula was used to calculate boundary dimension of plasma and shock wave velocity, and finally parameters were substituted into computational fluid dynamics simulation software to obtain solutions. Obtained analysis results could intuitively explain different morphological features and forming reasons between laser drilling in air environment and water environment in the experiment from angle of plasma shock waves. By comparing simulation results and experimental results, it could help to get an understanding of formation mechanism of microhole morphology, thus providing basis for further improving process optimization of laser drilling quality.

固体潤滑シートを用いたチタン合金の穴あけ加工におけるバリ高さに及ぼすドリル表面テクスチャリングの影響

This paper describes about the effect of drill surface texturing on height of back burr in titanium alloy drilling process with solid lubricating sheet. Titanium alloy is difficult to conduct drilling because titanium alloy is hard and ductile material. And the workers cannot use plenty of liquid coolant for preventing the productivity decline when the work places are above their heads in production fields. Therefore drills are exchanged frequently even though the cost increases. In this study, we measured the cutting force by a loadcell to know the effect of drill surface texturing and solid lubricating sheet on drilling process of work pieces made of Ti-6Al-4V. As the results, drill with rough textured rake surface showed high burr height in exit of Ti-6Al-4V. On the other hand, drill with rough textured flank surface showed low burr height only if drilling with solid lubricating sheet. Moreover, drill with the specific texturing on flank surface by wire electric discharge machining showed low burr height.

Analysis of thermal deformation and influencing factors in shrink-fitting assembly of aluminum alloy drill pipe

In shrink-fitting assembly process of aluminum alloy drill pipe with steel joint, the relationship between cooling water velocity, initial heating temperature, and thermal deformation of the steel joint is an important factor to ensure the long-term reliability of the connection and the performance. In this article, the shrink-fitting assembly experiment of aluminum pipe with steel joint was conducted and the accurate experimental data were obtained for temperature field. A finite element method was then applied to simulate the temperature field of steel joint and compared with the experimental results. Based on the thermo-elasticity theories, an analytical solution was developed to calculate the thermal deformation in radial direction within the same cross section. A least-square fitting procedure was used to determine the thermal deformation of steel joint. A relationship diagram among these three factors was established, which is particularly important in predicting the minimum heating temperature of steel joint and the minimum cooling water velocity. Based on the above analysis, a method to select the initial heating temperature and the cooling water velocity was provided and the optimum values of the magnitude of interference, the initial heating temperature, and the cooling water velocity were obtained.

Effect of cutting parameters on workpiece and tool properties during drilling of Ti-6Al-4V

Abstract The main aim of machining is to provide the dimensional preciseness together with surface and geometric quality of the workpiece to be manufactured within the desired limits. Today, it is quite hard to drill widely utilized Ti-6Al-4 V alloys owing to their superior features. Therefore, in this study, the effects of temperature, chip formation, thrust forces, surface roughness, burr heights, hole diameter deviations and tool wears on the drilling of Ti-6Al-4 V were investigated under dry cutting conditions with different cutting speeds and feed rates by using tungsten carbide (WC) and high speed steel (HSS) drills. Moreover, the mathematical modeling of thrust force, surface roughness, burr height and tool wear were formed using Matlab. It was found that the feed rate, cutting speed and type of drill have a major effect on the thrust forces, surface roughness, burr heights, hole diameter deviations and tool wears. Optimum results in the Ti-6Al-4 V alloy drilling process were obtained using the WC drill.

固体潤滑シートを用いたチタン合金の穴あけ加工におけるバリ高さに及ぼすドリル表面テクスチャリングの影響

固体潤滑シートを用いたチタン合金の穴あけ加工におけるバリ高さに及ぼすドリル表面テクスチャリングの影響