Aluminum Hole Research Articles

Assessing the effect of penetration length variations on dimensional measurements with X-ray computed tomography

From discussions in various standardization committees, testing material thickness influences on dimensional X-ray computed tomography (CT)—through variations of X-ray penetration-path lengths—has become a matter of great interest. Although this topic does not seem to be fully covered by the VDI/VDE 2630–1.3 guideline, other emerging documentary standards (ASME B89.4.23 and ISO/DIS 10360–11) are trying to address it in their guidelines. This paper evaluates variations in CT dimensional data when, to provide different penetration-path lengths to X-rays, enclosures of varying aluminum thickness are added (‘plus-shell’ condition) to surround three test workpieces during measurement. The test workpieces are two hole plates of square-shaped geometry with 28 drilled holes, one made of aluminum (48 mm × 48 mm × 8 mm) and the other made of steel (6 mm × 6 mm × 1 mm), and a multisphere artifact containing twelve ruby spheres of 4.0 mm nominal diameter. Geometrical features in the 0.5–66 mm range are studied. The main results show that while the deviations between CT and reference/calibrated data for uni-directional (center-to-center) lengths can be confined to a range of ±5 μm, with no significant differences in measurement results between no-shell and plus-shell conditions, bi-directional (edge-to-edge) lengths and form measurements have substantial differences—with deviations of up to 16 μm for form measurements in the aluminum hole plate in the no-shell condition and 42 μm when the same hole plate is housed within a highly irregular (gear-like) aluminum enclosure.

A Study on the Fabrication and Evaluation of Burnishing Drills for Aluminum Hole Making

A Study on the Fabrication and Evaluation of Burnishing Drills for Aluminum Hole Making

Nail Salon (봉선화 물 or Balsamina Water)

Nail Salon (봉선화 물 or Balsamina Water) Sara Son (bio) Ten stained fingernails later—afterthe twine, the balsamina lick, the magentamuddied paste. You woke the next day stainedthis side of orange, as your mother rolled green glass soju bottles on your calves. Whenyou first immigrated here, persuadedby the promise of Disneyland you knew fivewords: hello, thanks, sorry, bathroom, bye. Running vertical ridges on your nails (likelongitudes) drank the colored sap incapillary motion. Against gravity, againstdesire. Your mother travels ten thousand kilometers forward, seventeen hours backto lacquer the tips of a lady named Joan, jowlsstiffened smooth by a tapered syringe.In school, puncturing the aluminum hole of a juice box with a bent straw, you observedan overflow. Your fingers spilled over with stickyjuice. Up, up—motioned your teacher,pointing above at the cratered ceiling tiles that would sometimes drop eroding chunksof plaster cheese on your desk. Instead you heldthe carton over your head, the water of a fruit(maybe an apple) crying over you, not knowing that he meant to unbendthe straw, to tilt its craned neck upwards. [End Page 104] Sara Son Sara Son is a writer from Queens. She holds a BA from the Writing Seminars at Johns Hopkins University. Her writing has appeared in Smokelong Quarterly. She lives in Southern California with her husband and two dogs. She tweets, sometimes, at @saramjson. Copyright © 2022 University of Wisconsin Board of Regents

A novel sandwich structured phase change material with well impact energy absorption performance for Li-ion battery application

Thermal runaway in battery induced by rapid charging/discharging process and collision due to car accident are the two major safety issues. Therefore, we designed phase change materials (PCM) with collision energy absorption properties. The paraffin wax (PW) was mixed with expanded graphite (EG) to obtain an EG/PW composite material. After that, the EG/PW powder was pressed into the foamed aluminum (Al-f) hole to obtain an EG/PW/ Al-f sandwich structured PCM. The EG/PW/Al-f PCM was applied to a battery for thermal management and collision performance research. The results show that when the PCM was attached to the battery and the discharge is kept constant at 1 C/1.5 C (capacity) discharge rate, the battery temperature dramatically decreased; moreover, its temperature difference was more uniform than it was in the absence of PCM. Particularly, the EG/PW/Al-f PCM showed good impact energy absorption performance. The results of the impact experiment showed that when the battery suffered from a high-speed steel ball impact, the EG/PW/Al-f PCM attached to the surface of the battery could protect the battery well without any internal short circuit. Furthermore, the finite element model was developed to analyze the impact process of the battery. The results of the numerical solution match well with the experimental results; the experiment measured the indentation depth of a battery due to the steel ball falling from 2 m height. The results provide a new way to design PCM with both impact energy and heat absorption properties for battery application.

Friction Spot Joining (FSpJ) process of Aluminium AA6061-T6/Poly Vinly Chloride (PVC)

The goal of this research is to use a Friction Spot Joining (FSpJ) is a new technique which used for joining hybrid structures of metal-polymer composite. The FSpJ was proposed to join sheets of aluminum alloy of type AA6061-T6 and polymer of type polyvinyl chloride (PVC). The aluminum alloys sheets were of 3mm thickness, while the polymer sheets were of 5mm thickness. All sheets were manufactured with dimensions of 25*100 mm2. The aluminum sheets were drilled with two holes: the first of 8mm diameter with 1mm depth, the second hole was of the same pervious hole center with a penetrating hole diameter of d mm (2,4 and 6) the aluminum holes were made at a the center of the lap joint area. The process parameters included the rotating speed of the tool of 710, 900, 1120, 1400 and 1800 RPM, plunging depth of the tool of 0.1, 0.2, 0.3, 0.4 and 0.5 mm and pre-heating time of 5, 10, 15, 20 and 25 sec. The results indicated that all the specimens were joined successfully. The tested sample indicated that the failure of FSpJ joints occurred at two locations; the first at polymer side and the second was occurred by shearing the lap joint of specimens. The first type of failure indicated that the shear strength of the joined samples exceeded the shear strength of the polymer with a shear strength joint efficiency of more than 100%. The specimens that failed by shearing the polymer at the lap joint region were failed without dislocation the molten polymer from the aluminum hole cup. The shear force of the AL-PVC joints ranged from (704-1664N). The hole diameter exhibited the highest effect on the joint shear force followed by the plunging depth, rotating speed and pre-heating time of the rotating tool. The macrostructure examination and SEM tests indicate that a macro mechanical interlocking formed between the metal and filled hole which attributed to the main joining mechanism at the common surface.

Diagnostics of Residual Stresses in Bimetallic Aluminum–Steel Plates by Means of Laser Ultrasound and a Test Hole

The nature of changes in laser photoacoustic signals near small-diameter holes in aluminum and steel layers in a bimetallic plate obtained by hot rolling is investigated. The experimental results are compared with the solution of the classical Kirsch problem for stress distribution around a circular hole in a prestressed material. The possibility of estimating internal stresses by the laser photoacoustic method in combination with the method of drilling holes in industrial bimetallic plates is shown.

Joining of Aluminium Alloy AA6061-T6 to PVC Polymer by Friction Stir Lap joining Process

The aim of this research is to join sheets of aluminium alloy AA6061-T6 of 1.5 mm thickness with polymer polyvinyl chloride (PVC) of 4 mm thickness by a friction lap technique. Drill holes of 3, 4 and 5 mm were produced in the AA6061 specimens and a lap joint arrangement was set up with the PVC sheet. Six parameters were used in this technique: hole diameter, tool diameter, number of holes, rotating speed, linear speed, and tool plunging depth. The shear test results at the holes were analyzed by a Minitab program with the aid of the Taguchi method. IR thermometer was used to measure the temperature distribution at the joint. The results indicated that all the samples failed with shearing the PVC at the aluminium hole without dislocation the polymer. The maximum shear force is 1850N. The joint shear force increased by increasing the plunging depth and rotation speed of the tool and decreased by increasing the hole numbers and diameter of the aluminium specimen. The hole diameter beside the rotating and the linear speed exhibited the highest effect on the joint shear strength. The developed temperature during the joining process was an effective parameter on the joints quality. The SEM tests indicated that the joining between the aluminium and polymers occurred by a mechanical interlocking at the common surfaces.

Joining of Double Pre-Holed Aluminum Alloy AA6061-T6 to Polyamide PA using Hot Press Technique

The objective of this work is using a hot press technique to join a hybrid structure of aluminum alloy AA6061-T6 sheet of 1mm thickness together with polyamide PA sheet of 2mm thickness. The aluminum alloy specimen was pre-holed with two holes of 5mm diameter. The joining process was carried out with a lap joint configuration. Three different process parameters of the joining process were used: temperature (164, 172 and180°C), pressure (4, 7 and 10 bar) and time (1, 2.5 and 4 min.). The joints were tested by a shear test, macrostructure and scanning electron microscope (SEM) inspection. The design of the experiments (DOE) method was used to analysis the effect of the process parameters on the joint shear force. The DOE optimized the shear force of the joint with a maximum value of 1565 N at 177.5°C 4bar and 3.5min. The SEM examination indicated that the joining mechanism occurred by re-solidified the PA through the internal surface of the aluminum hole.

Joining of AA6061 to polyvinyl chloride via hot extrusion

Purpose The purpose of this paper is to join aluminium alloy AA6061 with polyvinyl chloride (PVC) sheets using the friction spot technique. Design/methodology/approach The AA6061 specimen was drilled with a semi-conical hole and put over the PVC specimen with a lap configuration. A friction spot technique was used to generate the required heat to melt and extrude the PVC through the aluminium hole. In this study, three process parameters were used: time, plunging depth and rotating speed of the tool. Thermal finite element model was built to analyse the process temperature. Effect of the process parameters on the joint shear strength and temperature was analysed using the design of experiments method. The microstructure investigation of the joint cross section was examined. Findings The input heat melted and extruded the polymer into the aluminium hole with the aid of tool pressure. A mechanical interlock was observed at the interface line between the polymer and aluminium. The scattered aluminium fragments into the molten polymer increased the shear strength of the joint. The hole diameter exhibited the highest effect on the joint strength compared with the other parameters. Specimen of minimum hole diameter recorded the maximum shear strength of 224 MPa. The proposed model gave a good agreement with the experimental data. Originality/value For the first time, the PVC was joined with AA6061 by the hot extrusion using the friction spot technique. The shear strength of joint reached 7.5 times of the base material (PVC).

Through Hole Aluminum Fabricated by the Extraction of Lubricated Metallic Wires

Through holes, which provide flow paths for coolants, are useful in the cooling panels of the turbine blades of airplane jet engines and the heat sinks of electronics devices in cars and computers. To date, through holes have been fabricated by the directional solidification of molten metals having dissolved hydrogen, the core-bar pulling method, the rod-dipping process, mechanical drilling, electron beam and laser ablation processing, and other processes. However, the fabricated holes are short and impractical. The aspect ratio of the length to the diameter of holes in aluminum is at most 10. Here we report through hole aluminum fabricated by extracting lubricated metallic wires embedded in a solidified aluminum melt. X-ray computed tomography showed that the through holes are very long with a maximum aspect ratio of 270. The hole sizes range from 102 to several 103 µm in diameter. Furthermore, the present technique can fabricate spiral and V-shaped holes in aluminum, a capability lacking in conventional perforation techniques. Thus, our methodology for producing through hole metals is expected to provide expanded opportunities for technologies such as heat sinks, turbines, biomaterials, and machine tools.

Comparative analysis of eddy current pulsed thermography and long pulse thermography for damage detection in metals and composites

Eddy current pulsed thermography (ECPT) and long pulse thermography (LPT) are two emerging non-destructive evaluation techniques that have been recently used for sub-surface defect detection in both metallic and composite components. This paper provides a comparative analysis of these two methods by focussing on the detection of flat bottom holes (FBHs) in both aluminium and carbon fibre reinforced plastic samples. Principal component analysis was used for the post-processing of thermal data in order to enhance the detection of FBHs with various diameters and depths. Results showed that LPT had a better performance for detecting FBHs in low-thermally conductive materials such as carbon fibre-reinforced thermoplastic composites, whilst ECPT revealed a superior performance for detecting FBHs in materials with higher thermal and electrical conductivity such as aluminium.

Dynamically tunable perfect absorption based on the phase transition of vanadium dioxide with aluminum hole arrays

Integrating plasmonic nanostructures with functional materials can further control over the optical resonant responses. A perfect absorber (PA) consisting of aluminum (Al) ring array intercalated with vanadium dioxide (VO2) disk is presented. The resonance wavelength of absorption peak can be tuned over a wide range in the visible (Vis) and near-infrared (NIR) regimes. The absorption peak shifts from 770 nm to 1336 nm while VO2 undergoes a structural transition from metallic phase (m-VO2) to insulator phase (i-VO2), resulting in a relative 73.5% wavelength shift. In addition, the absorption peak is strongly dependent on the height and radius of the ring disk as well as the period of lattice. Our work also suggests that the designed VO2-based absorber has the potential to overcome the difficulty in performing dynamically tunable resonances and near-unity absorbance with wide angle of incidence as well as weak polarization dependence.

CHARACTERIZATION OF ALUMINIUM FOAM PRODUCED FROM ALUMINIUM SCRAP BY USING CaCO3 AS FOAMING AGENT

In this paper, the characterization of aluminum foam produced from aluminum scrap by using CaCO3 as foaming agent was investigated. The results showed that the density of aluminum foam lies in the range of 0.40 to 0.60 g/cm3 and relative density ranged from 0.14 to 0.25 with high porosity between 78% and 85%. The microstructure examination of aluminum foam was done using XRD, SEM, and EDX. The obtained results indicate that, the aluminum holes were distributed uniformly in the matrix. The electrical resistance of aluminum foam was determined and compared with electrical resistance of dense aluminum. The results showed that the electrical resistance of aluminum foam is greater than the electrical resistance of dense aluminum. But, the thermal conductivity of aluminum foam is lower than thermal conductivity of dense aluminum. Energy absorption of aluminum foam was obtained by both impact and compression tests and it was observed that the energy absorption obtained from impact test is close to the energy absorption obtained from compression test. The produced aluminum foams can be used for high impact energy absorption applications.

Plasmonic Colour Filters Based on Coaxial Holes in Aluminium.

Aluminum is an alternative plasmonic material in the visible regions of the spectrum due to its attractive properties such as low cost, high natural abundance, ease of processing, and complementary metal-oxide-semiconductor (CMOS) and liquid crystal display (LCD) compatibility. Here, we present plasmonic colour filters based on coaxial holes in aluminium that operate in the visible range. Using both computational and experimental methods, fine-tuning of resonance peaks through precise geometric control of the coaxial holes is demonstrated. These results will lay the basis for the development of filters in high-resolution liquid crystal displays, RGB-spatial light modulators, liquid crystal over silicon devices and novel displays.

Quality Enhancement with Ultrasonic Wave and Pulsed Current in Electrochemical Machining

This paper presents the results of enhancement in Electrochemical Machining (ECM) by combining pulsed current and ultrasonic wave in flowing electrolyte through an electrode. Teflon coated stainless steel tubes were used as electrodes to produce deep holes in 6061-T6 aluminum. Material removal rate and hole quality were measured on a 3D optical profiler to study the effect of pulsed current amplitudes, pulsed frequencies, machining times, and ultrasonic wave amplitudes. Although pulsed current improves the removal rate, cavitation induced microjet suppresses the ionization process. The shockwaves from busting of cavitated bubbles break the aluminium tribromide by-product into fine powder that flows and polishes the workpiece surface. Although ultrasonic wave at 40 kHz compromised material removal rate, it significantly enhances the part quality by reducing surface roughness from 2.5 μm to 1 μm. The combined effect of pulsed current and ultrasonic wave reduces taper angle of ECM’ed holes sidewall from ∼11° to 1°.

Gamma radiation-induced thermoluminescence, trace element and paramagnetic defect of quartz from the Sambagawa metamorphic belt, Central Shikoku, Japan

This study analyzes the Thermoluminescence (TL) emissions for five emission bands, trace element concentrations and defects in quartz grains extracted from metamorphic rocks and quartz veins in the Sambagawa metamorphic belt, central Shikoku. An emission of 500nm with 195, 245, and 320–325°C glow peaks are observed through the lowest to highest grade samples. A 450nm emission band with intense 195 and 245°C glow peaks and a 320–325°C shoulder peak is found in the higher grade samples. A 570nm emission band with a 170°C glow peak is observed in the samples derived from the lower grade zones. These characteristics of TL emissions of quartz suggest that they can be an indicator for the identification of rock derived from different metamorphic grades. The higher metamorphic grade samples with 450nm emission bands in particular show higher intensities of the E1′ center. This relation indicates that the activation of the E1′ center in higher metamorphic conditions possibly contributed to the 450nm emission band. Also, the 500nm emission band is generally observed in the samples with the signal intensities of the Aluminum hole center, suggesting that the center is the source of this emission band. We also observed that the lower metamorphic grade samples contain lower signal intensities of the Aluminum hole center, despite higher aluminum concentrations. This inconsistency indicates that the formation of interstitial aluminum ions cause local lattice distortion regions, where self-trapped excitons can be formed and presumably provide the 570nm emissions.

Double-Layer Metallic Holes Lens Based on Continuous Modulation of Phase and Amplitude

We have demonstrated numerically a lens design based on continuous modulation of both phase and amplitude utilizing array of double-layer metallic aluminum holes filled with silicon dioxide. The tuning range is 0-π and 0-0.3 for phase and amplitude, respectively, at wavelength 365 nm, allowing flexible lens design. Two lenses are designed and compared. At wavelength 365 nm, the lens based on pure phase modulation generates a 600-nm hot spot at a distance of 6.5 μm, while the phase-amplitude-modulation-based lens leads to an improved focusing spot size of 450 nm, which is beyond the diffraction limit 608 nm and the superoscillation criterion 462 nm. An example of subwavelength superoscillation focusing (0.32λ) is also demonstrated with a continuous amplitude modulated lens, which shows small sidelobe and broad view field. Our approach shows great potential in superoscillation lens design and can be applied to other optical spectrum ranges as well.

Plasmonic Fluorescence Enhancement of DBMBF2 Monomers and DBMBF2–Toluene Exciplexes using Al-Hole Arrays

The optical properties of aluminum hole arrays fabricated via colloidal lithography were investigated. By tuning the hole diameter and hole spacing independently, their influence on the Bloch wave–surface plasmon polariton (BW-SPP) and localized surface plasmon resonances resonances (LSPR) could be identified. The aluminum hole arrays were used to enhance the fluorescence of a dibenzoylmethanatoboron difluoride (DBMBF2) dye. The dye exhibits the advantageous property of forming an exciplex with aromatic compounds. The interaction of DBMBF2 monomer fluorescence and DBMBF2–toluene exciplexes with Al hole arrays is studied. Furthermore, the respective roles of the BW-SPPs and LSPRs were studied through tuning of the plasmon resonances from the UV excitation wavelength (λext = 385 nm) through the visible emission range (400–550 nm). Monomer emission was predominately enhanced by BW-SPPs while exciplex emission showed a contribution from both BW-SPPs and LSPRs. Fluorescence enhancement of 3.8 was observed for DBMBF2–toluene exciplex emission from 26 nm thick polymer films. Aluminum hole arrays are shown to be attractive structures for fluorescence enhancing applications with excitation in the UV and stable oxide coatings.

The importance of holes in aluminium tris-8-hydroxyquinoline (Alq3) devices with Fe and NiFe contacts

To study the dominant charge carrier polarity in aluminium tris-8-hydroxyquinoline (Alq3) based spin valves, single Alq3 layer devices with NiFe, ITO, Fe, and aluminium electrodes were fabricated and characterised by Time of Flight (ToF) and Dark Injection (DI) techniques, yielding a lower hole mobility compared to electron mobility. We compare the mobility measured by DI for the dominant carrier injected from NiFe and Fe electrodes into Alq3, to that of holes measured by ToF. This comparison leads us to conclude that the dominant charge carriers in Alq3 based spin valves with NiFe or Fe electrodes are holes.

Effect of repeated insertions into a mesoscale pinhole assembly: Case of interference fit

The importance of micro-scale tolerance has increased due to the growing demands for micro component devices. However most existing standards and previous studies of tolerances have focused on milli-scale assemblies. In this study, a micro-scale pinhole assembly was analyzed, and the forces obtained under repeated insertions were measured. Tungsten carbide pins with different tip edges were fabricated and inserted into an aluminum hole element. From the force-measurement results, most of the plastic deformation occurred during the first insertion, as repeated insertions showed the same magnitude of force. For a given micro-scale tolerance, tools with sharpened tip edges had larger insertion forces because they had larger frictional areas. The shear stress values obtained during the insertions were calculated from the measured forces and compared with each other. The shear limit under elastic deformation was analyzed using a thick-walled cylinder model. During the repeated insertions, the calculated shear limit matched the experimental results well, and it was not affected by the interference or pin diameter. The contribution of this study is a shear stress model for repeated interference fits of a pinhole assembly with micro-scale tolerance, considering different pin-tip edges.