Diamond Blade Research Articles

Sub-Fiber Scale Precision Dicing of Aramid Fiber-Reinforced Plastic Composites

Aramid fiber-reinforced plastic (AFRP) composites are widely used in aerospace, rail transit, marine and military industries, due to their high specific strength, high impact resistance, fatigue resistance and excellent designable properties. In order to meet different application requirements, cutting processes need to be carried out, such as window opening, edge cutting and slit cutting. However, the characteristics of high tensile strength and toughness, low interlaminar strength, non-uniformity and anisotropy make AFRP composites a difficult-to-machine material. They are prone to produce rough cutting surfaces and cutting damages including burr, wire drawing, delamination, resin burn, material flanging, etc. To solve this problem, the ultra-thin diamond dicing blade was used for high-speed cutting of AFRP composites in sub-fiber scale in this research. The influence of process parameters on cutting force, cutting temperature, maximum spindle current, tool wear and cutting surface quality were investigated by establishing the cutting force model, L16(45) orthogonal experiment, single factor experiment, range analysis and variance analysis. The theoretical and experimental results show that cutting AFRP composites with ultra-thin diamond dicing blade can obtain smooth surfaces without common cutting damages. When the cutting speed is 91.11 m/s (spindle speed n = 30,000 r/min), the cutting depth is 0.2 mm and the feed speed is 5 mm/s, the surface roughness Ra can be as low as 32 nm, which realize the precision cutting of AFRP composites.

C5+ ion irradiated ZnSe optical waveguide operating from near-infrared to mid-infrared wavelength band

We have manufactured an optical ridge waveguide in ZnSe crystal utilizing techniques of C5+ ion irradiation and precise diamond blade dicing. From near-infrared to mid-infrared band, the waveguide supports single-mode transmission and the propagation losses have been reduced as low as 0.8 dB/cm (λ = 1.064 µm), 0.6 dB/cm (λ = 2.2 µm) and 0.4 dB/cm (λ = 4 µm) after a series of annealing treatments. The refractive index profile of the waveguide is reconstructed and the simulated near-field modal profile fits well with the experiment. The Raman spectrum of the waveguide and substrate indicates there is no large lattice damage after C5+ ion irradiation.

Second harmonic generation from precise diamond blade diced ridge waveguides

Carbon ion irradiation and precise diamond blade dicing are applied to fabricate Nd:GdCOB ridge waveguides. The propagation properties of the fabricated Nd:GdCOB waveguides are investigated through experiments and theoretical analysis. Micro-Raman analysis reveals that the Nd:GdCOB crystal lattice expands during the irradiation process. Micro-second harmonic spectroscopic analysis suggests that the original nonlinear properties of the Nd:GdCOB crystal are greatly enhanced within the waveguide volume. Under pulsed 1064 nm laser pumping, second harmonic generation (SHG) at 532 nm has been achieved in the fabricated waveguides. The maximum SHG conversion efficiencies are determined to be ∼ 8.32 %⋅W−1 and ∼ 22.36 %⋅W−1 for planar and ridge waveguides, respectively.

Simulation and Analysis on the Influence of Diamond Blade Cutting Parameters of Grinding Wheel Dicing Saw

In this paper, the cutting model of the dicing saw based on ANSYS simulation was established. Through coupling analysis, the force distribution and deformation of the cutting chip of the diamond grinding wheel cutter were simulated. The full-parameter solid modeling of the aerostatic spindle was carried out to analyze the influence of fixed cutter diameter, machining parameters and condition changes on spindle vibration. The blade thickness, whether to add coolant or not, and the influence of different spindle speed on spindle vibration were studied. The influence of different blade thickness on spindle vibration when the tool diameter is fixed is analyzed. The effect of different tool diameters matching different tool thicknesses on spindle vibration is discussed. Analyze the vibration of the spindle under different diameters. In the experiment, the spindle vibration was measured by changing the cutting parameters, and the root mean square value was used as the evaluation index to analyze the influence of the cutting parameters of the grinding wheel’s diamond blade. The vibration of different diameters and different spindle directions was analyzed. The experimental results show that the above analysis method is feasible within the allowable error range, which provides a powerful reference for the future theoretical research.

Structure Integrity Analysis on Nickel–Diamond Blade in Dicing of Hard-brittle Ceramic Die

Dicing operation in cutting hard-brittle ceramic die using nickel–diamond blade causes cracked or chipped die, accelerated tool wear and, ultimately, shortage of blade lifetime. This study aims to analyse the structural integrity of dicing blade in terms of tool wear, surface roughness, microstructure and elements during dicing. The measurements of wear blade on the blade are made by confocal microscope, whereas surface and elemental analyses are carried out with EDX SEM. Results show that the volumetric wear rate of blade is 20%, similar to roughness. The microstructure of the blade changes with occurrence of Aluminium owing to abrasive wear mechanism during cutting.

Surface Roughness after Milling of the Al/CFRP Stacks with a Diamond Tool.

This study presents the results of research on the surface quality of hybrid sandwich structures after milling with a diamond blade tool. It identifies the effects of feed and machining strategy on the roughness and topography of the surface. It provides an analysis of Ra and Rz surface roughness parameters as well as Sp, Sz, and Sv surface topography parameters. The processed object was a two-layer sandwich structure consisting of aluminium alloy 2024 and CFRP (carbon fibre-reinforced polymer) composite. The minimum values of the Ra and Rz surface roughness parameters were obtained on the aluminium alloy surface, whereas the maximum values were obtained on the CFRP surface. The same was true for the 3D surface roughness parameters—the lowest values of Sp, Sz, and Sv parameters were obtained on the surface of the metal layer, while the highest values were obtained on the surface of the composite layer (the maximum value of the Sp parameter was an exception). A surface topography analysis has revealed a targeted and periodic pattern of micro-irregularities for the vast majority of the samples considered. The statistical analysis shows that the surface roughness of the aluminium alloy was only affected by the feed rate. For the CFRP, the feed rate and the interaction of milling strategy and feed rate (S fz) had a statistically significant effect. The obtained results provide a basis for designing such sandwich element processing technology, for which differences in roughness and topography parameters for the component materials are lowest.

Second harmonic generation in precisely diced KTiOAsO4 ridge waveguides

We demonstrate KTiOAsO4 (KTA) ridge optical waveguides by precise diamond blade dicing of ion-irradiated planar waveguides. The guiding and spectroscopic properties of ridge waveguides have been investigated. The original properties of the z-cut KTA crystal have been well preserved in the ion-irradiation area. Under optical excitation of a 1064-nm pulsed laser, second harmonic generation (SHG) of green laser at 532 nm is generated from waveguide structures, demonstrating a maximum output power of 1.71 mW and a SHG conversion efficiency of 4.28%. The results in this work suggest promising applications of diamond blade diced KTA waveguides in integrated photonics and nonlinear optics.

Optical planar and ridge waveguides formed in Er3+-doped germanate glass by ion implantation and precise diamond blade dicing.

In this work, we report on the preparation and characterization of the planar and ridge optical waveguides in the Er3+-doped germanate glass by combining hydrogen ion implantation and precise diamond blade dicing. The nuclear energy loss and the implantation depth were calculated by the SRIM 2013 software. The refractive index profile was obtained by the reflectivity calculation method. The dark-mode spectrum and the near-field intensity distribution were measured by the prism coupling system and end-face coupling technique, respectively. This work has important reference significance for the development of Er3+-doped germanate glass active devices in the optical communication field.

A New Genus and Species of Grass, Eograminis balticus (Poaceae: Arundinoideae), in Baltic Amber

Premise of research. This investigation was undertaken to describe a multifloral grass spikelet enclosed in Baltic amber. The fossil, described in the new genus Eograminis, represents the first definite grass to be described from Baltic amber as well as the first fossil member of the subfamily Arundinoideae. The discovery adds a new plant group to the extensive flora previously described from Baltic amber and provides insights into the ecology of the forest habitat. It also supplies morphological and developmental features that existed in early Cenozoic grasses and establishes a calibration point for future phylogenetic studies regarding the origin and splitting of genera in the subtribe Moliniinae. Methodology. The piece of amber containing the fossil was reshaped with a diamond blade lapidary trim saw, a belt sander, and a bench polisher until it was possible to view the grass spikelet from all angles. Because of the excellent preservation of the spikelet, observations of the glumes, paleae, and lemmas could be made under direct light with a stereoscopic and compound microscope. Pivotal results. After the features of the spikelet are characterized, it is described as Eograminis balticus gen. et sp. nov. (Poaceae: Arundinoideae). The new genus is characterized by the presence of stomata with well-developed dome-shaped subsidiary cells, parallel guard cells, and rows of crenulated and noncrenulated epidermal cells with long and short cells and silica bodies. Conclusions. The spikelet has some features of members of the extant genus Molinia Schrank in the tribe Molinieae, subtribe Moliniinae, a wetland genus with extant species concentrated around the Baltic Sea. However, the sparse scabrosity over the lemma veins, minute or absent keel hooks on the paleae, and bicellular or absent microhairs of Molinia spp. separate it from the fossil. The presence of an immature orthopteran and an “Alternaria-like fungal spore” associated with the fossil grass provides data on the microhabitat of the fossil grass.

Suturing of the Arachnoid Membrane for Reconstruction of the Cisterna Magna: Technical Considerations

Postoperative cerebrospinal fluid (CSF) fistula following cranial or spinal surgery is associated with increased morbidity and mortality. To prevent CSF fistulas, various techniques have been described. Here, we describe the arachnoid membrane continuous-running suture technique in cisterna magna reconstruction for preventing postoperative CSF leakage. After craniotomy and dural opening, the incision of the arachnoid of the cisterna magna was performed using a diamond blade. To prevent the arachnoid from drying out and shrinking during surgery, it was periodically irrigated with warm saline solution. Posterior fossa surgery was performed. When closing the membranes, the arachnoid membrane was closed with the running-suture technique. After the first surgical knot was made in the cranial end of the arachnoid opening, continuous suturing with a 2-mm distance between the stitches was performed without stretching them. After every 3 stitches, the free end of the thread was pulled gently along the suturing axis, and the edges of the arachnoid were closed. After the arachnoid edges were approximated, the surgical knot was tied. Watertight closure was checked byperforming the Valsalva maneuver at the end of the surgery. No CSF leakages were observed after surgery. Arachnoid membrane suturing seems to be safe and effective in preventing postoperative CSF leakage and CSF-related complications. Using continuous running suturing alone, without any sealant, might beeffective in cases with untraumatized arachnoid membrane.

Experimental Analysis of Abrasive Diamond Tool Wear and their Cutting Force in Stone Machining Process

Stone machining with a diamond tool is a common procedure for producing both standard items and design shapes, such as tiles, slabs and so on. During the entire deep sawing process of a granite work piece with finite length cutting procedure in stone processing, force components acted on the saw-blade. The work is split into two parts: theoretical and practical. The theoretical section discusses the features of diamond blades, cutting process methodology, and stone mining and processing methods. The practical portion of the project focuses on the wear of diamond blades when cutting stone, notably granite. The overall weight of the cutting blade and the loss of tooth height as a function of time are used to determine blade wear for two cutting blades from different manufacturers. There is a linear relationship between the two measured values. The findings serve as the foundation for a cost-benefit analysis of both diamond wheels.

Optical planar and ridge waveguides in terbium scandium aluminum garnet crystal fabricated by ion implantation and precise diamond blade dicing

Terbium scandium aluminum garnet crystal is a promising material which has excellent characteristics for magneto-optical devices. We report on the fabrication of optical planar and ridge waveguides in the terbium scandium aluminum garnet by using combination of helium ion implantation and precise diamond blade dicing. The conditions for the ion implantation are an energy of 400 keV and a fluence of 6 × 1016 ions/cm2. The rotating velocity and cutting speed of the diamond blade were set to be 20,000 rpm and 0.1 mm/s, respectively. The implantation depth and distributions of energy loss were calculated by the stopping and range of ions in matter 2013. The refractive index distribution and the dark-mode spectrum for the implanted planar waveguide were obtained by the reflectivity calculation method and the prism coupling system, respectively. The near-field intensity profiles of both the planar and ridge waveguides were measured by the end-face coupling technique. The optical guiding properties of the terbium scandium aluminum garnet waveguides suggest that they can serve as candidates for optical waveguide isolators.

Mid-infrared ridge waveguides fabricated in CaF2 crystal by the technique of O5+ ion irradiation.

The fabrication of ridge waveguides in calcium fluoride (CaF2) crystal working at the mid-infrared wavelength was studied. First, the planar waveguide was fabricated by using O5+ ion irradiation, and then the ridge waveguide structure was manufactured by precise diamond blade dicing. The propagation loss was measured by end-face coupling arrangement, and then annealing treatment was implemented to optimize the waveguide performance, and the propagation loss was finally reduced to 0.5 dB/cm. We measured the Raman spectra of the waveguide and substrate to observe the damage to the material lattice caused by O5+ ion irradiation technology.

Development and post-dicing wet release of MEMS magnetometer: an approach

PurposeSi-based micro electro mechanical systems (MEMS) magnetometer does not require specialized magnetic materials avoiding magnetic hysteresis, ease in fabrication and low power consumption. It can be fabricated using the same processes used for gyroscope and accelerometer fabrication. The paper reports the dicing mechanism for the released MEMS xylophone magnetic sensor fabricated using wafer bonding technology and its characterization in ambient pressure and under vacuum conditions. The purpose of this paper is to dice the wafer bonded Si-magnetometer in a cost-effective way without the use of laser dicing and test it for Lorentz force transduction.Design/methodology/approachA xylophone bar MEMS magnetometer using Lorentz force transduction is developed. The fabricated MEMS-based xylophone bars in literature are approximately 500 µm. The present work shows the released structure (L = 592 µm) fabricated by anodic bonding technique using conducting Si as the structural layer and tested for Lorentz force transduction. The microstructures fabricated at the wafer level are released. Dicing these released structures using conventional diamond blade dicing may damage the structures and reduce the yield. To avoid the problem, positive photoresist S1813 was filled before dicing. The dicing of the wafer, filled with photoresist and later removal of photoresist post dicing, is proposed.FindingsThe devices realized are stiction free and straight. The dynamic measurements are done using laser Doppler vibrometer to verify the released structure and test its functionality for Lorentz force transduction. The magnetic field is applied using a permanent magnet and Helmholtz coil. Two sensors with quality factors 70 and 238 are tested with resonant frequency 112.38 kHz and 114.38 kHz, respectively. The sensor D2, with Q as 238, shows a mechanical sensitivity of 500 pm/Gauss and theoretical Brownian noise-limited resolution of 53 nT/vHz.Originality/valueThe methodology and the study will help develop Lorentz force–based MEMS magnetometers such that stiction-free structures are released using wet etch after the mechanical dicing.

Dual-color upconversion luminescence emission from Er:LiNbO3 on-chip ridge waveguides

Dual-color upconversion luminescence of Er3+-doped (0.1% mol) lithium-niobate-on-insulator (Er:LNOI) on-chip ridge waveguides is observed under the excitation of a continuous-wave 980-nm semiconductor laser, emitting both blue (at 450 nm) and green (at 528.3 nm) fluorescence emissions. The on-chip waveguides, with a propagation loss of around 3 dB/cm at 1550 nm, are fabricated by diamond blade dicing technique. The experimentally observed waveguiding modal profiles are in fairly good agreement with simulation results, indicating good quality of the fabricated waveguides. We believe this work will benefit the development of LiNbO3-based integrated photonics.

FEM and Analytical Modeling of the Incipient Chip Formation for the Generation of Micro-Features.

This paper explores the modeling of incipient cutting by Abaqus, LS-Dyna, and Ansys Finite Element Methods (FEMs), by comparing also experimentally the results on different material classes, including common aluminum and steel alloys and an acetal polymer. The target application is the sustainable manufacturing of gecko adhesives by micromachining a durable mold for injection molding. The challenges posed by the mold shape include undercuts and sharp tips, which can be machined by a special diamond blade, which enters the material, forms a chip, and exits. An analytical model to predict the shape of the incipient chip and of the formed grove as a function of the material properties and of the cutting parameters is provided. The main scientific merit of the current work is to approach theoretically, numerically, and experimentally the very early phase of the cutting tool penetration for new sustainable machining and micro-machining processes.

Dental Pulp Autotransplantation: A New Modality of Endodontic Regenerative Therapy—Follow-Up of 3 Clinical Cases

The aim of this study was to develop a novel method of endodontic therapy, which we refer to as dental pulp autotransplantation. Three patients (2 males and 1 female) were selected for endodontic treatment of a uniradicular premolar and extraction of a third molar (without odontosection). Electric assessment of pulp vitality and computed tomographic imaging were undertaken followed by endodontic access and instrumentation using triantibiotic solution for irrigation in the host tooth. A few minutes before the transplant procedure, the third molar was extracted, the tooth was sectioned with a diamond blade in a low-speed handpiece, and the pulp was carefully removed. After premolar instrumentation, the harvested and preserved pulp tissue was reinserted into the root canal followed by direct pulp capping performed using Biodentine (Septodont, Saint-Maur-des-Fossés, France), a liner of resin-modified glass ionomer cement and composite resin restoration. The teeth were followed up for at least 12 months after the procedures and were analyzed using computed tomographic imaging, electric pulp vitality testing, and Doppler ultrasound examination. At the 3- and 6-month follow-ups, positive pulp vitality and regression of periapical lesions were verified. After 9–12 months, all teeth were revascularized as determined by Doppler imaging, and the tooth vitality was reestablished with no signs of endodontic/periodontal radiolucency or complications. Within the limitations of the study, considering that it was a case series with only 3 patients, we described a highly innovative procedure of pulp autotransplantation, which appears to be feasible, highlighting the potential for clinical application of pulp regeneration using this new modality of endodontic therapy.

A novel evaluation method for thin films mechanical characterizations using cutting system

In this study, we suggest a nano-cutting system to determine the shear strength of the thin films using fracture mechanics analysis of the diamond blade. Based on Merchant's cutting model, we analyze the thin films cutting process with regard to shear angle and resistant forces as initiation of the yield in the chip to establish a direct correlation between the cutting forces and the shear strength. Validating the proposed method was conducted using homogenous polycarbonate disk showing similar shear strengths between different cutting directions. Next, we examined a thin copper electroplated film used in traces of printed circuit board. A thin copper film was examined and found the intrinsic shear strength (307.5 MPa) and adhesion force (44 N/m) between the film and substrate. The result was comparable with tensile strength values reported in the literatures. Finally, we used SEM to visually verify the feasibility of nano-cutting technique to determine thin film properties.

Watt-level 775 nm SHG with 70% conversion efficiency and 97% pump depletion in annealed/reverse proton exchanged diced PPLN ridge waveguides.

We report on fabrication of ridge waveguides formed in congruent periodically poled lithium niobate substrates using annealed and reverse proton exchange followed by diamond blade dicing. 1 W of second-harmonic generation at 775 nm has been obtained in a single-pass in 50 mm long ridge waveguides with internal conversion efficiency of 70%. At this power level, 97% pump depletion has been reached. Although elevated temperature operation and ridge geometry help to mitigate photorefractive damage (PRD) effects, nevertheless, at even higher second harmonic outputs significant power drop with blue shift and distortion of the SHG tuning curve have been observed indicating an onset of PRD.

Fiber-optic sensor measuring spatial distributions of refractive index and temperature.

In this work, we present a fiber sensor designed to measure simultaneously spatial inhomogeneities of the refractive index and temperature in liquid media, for example, induced by biochemical reactions. The sensor's constituent elements are Fabry-Perot microresonators fabricated in standard single-mode optical fibers by diamond blade dicing. To allow simultaneous measurements of different refractive indices, the sensor comprises two open cavities approximately 2 mm apart. With a small Si inlay inserted into one of the resonators used for temperature measurements, the sensor allows for immediate compensation of crosstalk between temperature- and composition-induced fluids' refractive index changes. The measurements were evaluated by phase tracking of the characteristic Fourier transform components of the sensor's backreflected spectra. The temperature sensitivity of the Si inlay is 0.063 rad/°C (79 pm/°C), and an accuracy of 0.01°C is obtained. Meanwhile, the two refractive index sensing (open) cavities show a sensitivity of 1168 and 1153 nm/RIU for temperature-compensated measurements. Finally, the sensor performance to measure spatial distributions is demonstrated by measuring the diffusion behavior of sucrose in water, which allows precise monitoring of hydration effects and breaking of bonds at elevated temperatures.