Diamond Abrasives Research Articles

Development of a Diamond Composite in the NI-CO-FE3P-SN-WC System Via Free Sintering for Use in Multi-Find Diamond Pearls

Objective: The main objective of this study is to manufacture a diamond composite with a metallic matrix based on Ni-Co-Fe3P-Sn-WC, using the Free Sintering process through cold uniaxial compaction, intended for the production of pearls for diamond wire saws, used in cutting ornamental stones. Theoretical Framework: The multi-wire technology represents an advancement in cutting ornamental stone blocks, allowing the simultaneous production of multiple slabs. Powder metallurgy is the predominant technique used in the manufacturing of pearls for diamond wire saws. Through testing, including scanning electron microscopy (SEM) and shear tests, it is possible to evaluate the alloy's strength, diamond crystal adhesion, and failure behavior of the alloy. Methodology: The adopted methodology involves the processing and characterization of pearls for diamond wire saws, following the techniques of powder metallurgy. Initially, parametric calculations were performed using Excel, providing a basis for subsequent analyses. Diamond-coated pearls were produced with different proportions of constituent elements, and uniaxial compressive strength tests and microstructural characterization were conducted to evaluate the results. Results and Discussion: In the adhesion tests to the metal tube, the pearls produced with the NICOFE alloy showed similar performance to the commercial pearls "A" and "B," with satisfactory direct shear strength values. However, some point defects were observed, such as porosity in the transition zone, creating a weaker bond, negatively impacting the final strength of the composite. Analysis of the commercial samples indicated that diamond abrasion was not related to the composition of the sintered alloy. Research Implications: This research suggests significant economic and technological implications, such as the development and nationalization of technology for the ornamental stone industry. The use of the NICOFE alloy could strengthen the local industry by providing a viable and more accessible alternative for the production of diamond pearls. Originality/Value: The NICOFE blend presents technical advantages for manufacturing diamond wire pearls, highlighting the environmental benefits from reduced cobalt use and economic advantages by offering more accessible materials for the ornamental stone industry.

A Classification and Segmentation Model for Diamond Abrasive Grains Based on Improved Swin-Unet-SAM

The detection of abrasive grain images in diamond tools serves as the foundation for assessing the overall condition of the tools, encompassing crucial aspects of diamond abrasive grains like the quantity, size, morphology, and distribution. Given the intricate background textures and reflective characteristics exhibited by diamond images, diamond detection and segmentation pose a significant challenge. Recently, numerous defect detection methods based on machine learning and deep learning have emerged. However, several issues persist, such as detection accuracy and the interference caused by intricate background textures. The present work demonstrates an efficient classification and segmentation network algorithm that combines Swin-Unet with SAM (Segment Anything Model) to alleviate the existing problems. Specifically, four embedding structures were devised to bridge the two models for iterative training. The transformer blocks within the Swin-Unet model were enhanced to facilitate classification and coarse segmentation, and the mask structure in SAM was refined to enable fine segmentation. The experimental results show that under a small sample dataset with complex background textures, the average index values of ACC (accuracy), SE (Sensitivity), and DSC (Dice Similarity Coefficient) for the classification and segmentation of diamond abrasive grains reached 98.7%, 92.5%, and 85.9%, respectively. Compared with the model before improvement, its ACC, SE and DSC increased by 1.2%, 15.9%, and 7.6%, respectively. The test results, based on four different datasets, consistently indicated that this model has excellent segmentation performance and robustness and has great application potential in the industrial field.

Retention and interfacial failure mechanism of single diamond grains in resin-bonded grinding tools

Abrasive grains and the associated bonding agent are the two significant components in the manufacturing of fixed abrasive machining tools. The material properties and interfacial bonding behavior between the grains and the bonding matrix determine machining performance. In precision machining processes with diamond abrasives, the primary failure modes of fixed abrasive tools are grain dislodgement and premature loss, leading to abrupt change in machining load and ultimately causing inaccurate and inefficient machining performance. This study develops a comprehensive model for understanding abrasive grain retention and interfacial failure mechanisms in resin-bonded diamond tools. Finite element analysis of a single diamond grain embedded in a resin matrix was conducted to examine the influence of the grain shape, protruding height, and orientation angle on critical interfacial failure force. A series of single diamond scratching experiments validated the model, revealing that the maximum retention force reached 43.56 N for grains with a 0.9 mm protruding height and a 60° orientation angle. The results also show that, within a specific grain size range, grain shape—quantified by the sphere deviation coefficient proposed in this paper, has the greatest impact on retention and failure behavior. Protruding height plays a secondary role, while the contribution of orientation angle is minimal. These findings provide valuable insights for the design, manufacture, and optimization of precision abrasive machining tools, particularly for applications requiring high precision and reliability.

Investigation on mechanism of mechanical activation and chemical reactions in CMP of diamond assisted by hydroxyl free radicals

Chemical mechanical polishing (CMP) is a crucial manufacturing process for diamond substrate applications. However, due to the extremely high hardness and chemical stability of diamond, its CMP efficiency is extremely low. This study aims to achieve microscopic simulation of atomic oxidation removal at the three-phase interface between diamond abrasive particle, diamond substrate, and hydroxyl free radicals (∙OH) aqueous solution. The mechanical activation behavior, microscopic mechanism, and feasibility of elementary reactions in the ∙OH aqueous solution environment was studied using various perspectives of radial distribution function, central atomic coordination state, atomic bonding and removal forms, energy, electron orbitals, and density functional theory (DFT). The simulation results indicate that during the process of diamond atomic oxidation removal, the atomic density at the first adjacent position centered on one atom decreases, and the stable covalent bond structure is disrupted, resulting in an amorphous phase transition. The chemical adsorption reaction generates C-O and C–H bonds. The C atoms mainly separate from the diamond substrate by the forming products such as carbon monoxide (CO), carbon dioxide (CO2), and carbon chains. The mechanical activation behavior indirectly reduces the activation energy of chemical reactions, while increasing the absolute value of adsorption energy and improving the ability of chemical adsorption solution atoms H and O, as well as ∙OH groups. Based on DFT, it has been verified that the intrusion process of ∙OH groups in the elementary reactions involving the typical product C*O2 is an exothermic reaction that can occur spontaneously, and the energy barrier needs to be overcome by the mechanical action of abrasive particles. At the same time, the energetics of the oxidation of diamond C atoms to generate C*O2 have successfully confirmed that the combined action of ∙OH and diamond abrasive particles is expected to achieve efficient oxidation removal and finishing polishing of diamond atoms.

A novel subsurface damage model in diamond wire sawing of silicon wafers

The subsurface damages (SSDs) generated during fixed abrasive diamond wire sawing (DWS) of silicon wafers can reduce the fracture strength and increase the breakage probability of these wafers. It is crucial to accurately evaluate these SSDs. A theoretical model of SSD depth is developed for the fixed abrasive DWS of silicon wafers considering the size effects of material properties, micro-geometries of abrasive grits, and inclination/interaction effects of subsurface cracks. A series of silicon wafers are processed, and the silicon material properties, diamond wire parameters, and surface/subsurface morphologies of silicon wafers are measured. The model is experimentally validated and then used to study the effects of processing parameters on inclination/interaction effects, cutting behaviors, and SSDs. The results show that the model has a relative error of less than 5.0% after revealing that the inclination/interaction parameters, cutting behavior parameters, and SSD depth almost follow a normal distribution, with a maximum distribution probability ranging from 30% to 50%. The average inclination angle is approximately 30°, the average cutting depth is in the range of one to two hundred micrometers, the average load is a few millinewtons, and the SSD depth is in the range of a few micrometers. With an increasing density of abrasive grit, a decreasing feed rate, or an increasing wire speed, the interaction effect becomes more pronounced, while the inclination angle, cutting depth, load, active grit ratio, and SSD depth decrease. When the protrusion height increases, or the half sharpness angle or tip radius of abrasive grit decreases, there is an increase in the cutting depth, load, active grit ratio, or SSD depth. The inclination angle decreases as the protrusion height, half sharpness angle, or tip radius increases. This research helps to understand the cutting mechanism and evaluate the SSDs during the DWS of silicon wafers.

Force rheological polishing of polycrystalline magnesium aluminate spinel using agglomerated diamond abrasive

The high hardness and polycrystalline structure of polycrystalline magnesium aluminate spinel (PMAS) present significant challenges in achieving high-precision processing, particularly during polishing. Issues such as low processing efficiency and grain effects can compromise processing accuracy, surface quality, and optical performance. To address these challenges and enhance both polishing efficiency and surface quality, this study employed agglomerated diamond (AD) abrasives and single crystal diamond (SCD) abrasives in force rheological polishing (FRP). The experimental results revealed that the lowest surface roughness (Sa) and optimal selective material removal were achieved using 25 μm AD abrasives, particularly those agglomerated with 0.2 μm SCD abrasives. This approach reduced Sa from 146.1 nm to 4.6 nm, peak-to-valley height difference (Sz) from 1329 nm to 69.3 nm and achieved a material removal rate (MRR) of 228.8 nm/min. Conversely, polishing with 1 μm SCD abrasives resulted in poorer selective material removal, with Sz decreasing from 1265.1 nm to 280.9 nm and Sa decreasing from 138.3 nm to 27.6 nm, although it exhibited the highest MRR of 323.64 nm/min. The superior polishing results obtained with AD abrasives, compared to SCD abrasives of the same size, can be attributed to the polycrystalline-like structure of AD abrasives, which exhibit more micro cutting edges. Additionally, the surface and subsurface damage after polishing with AD abrasives was analyzed. The results indicated that material removal of PMAS using AD abrasives was effective in FRP, resulting in minimal lattice distortion. This study provides both theoretical and experimental foundations for polishing PMAS using larger-sized AD abrasives in FRP.

Influence of Binding Agent on the Cutting Performance and Friction Wear Characteristics of Catalytic Composite Abrasive Cluster

To improve the polishing efficiency and process stability of catalytic composite abrasive clusters (CCAC), CCAC containing different binding agent ratios was investigated. Five groups of CCAC with different binding agent ratios were prepared for friction chemical polishing of silicon carbide (SiC), respectively. Based on material removal rate (MRR) and surface roughness (Ra) as evaluation metrics, the polishing performance of five groups of CCAC were compared. Subsequently, wear experiments were carried by block shaped CCAC with diameter of 1.6 mm, as well as single crystal diamond (SCD) abrasives with the same particle size. The friction coefficient and the cross-sectional area at the worn area of wear were measured to evaluate the effect of binding agent content on the continuous cutting performance of the abrasive as well as on the tribological properties. The experimental results showed that #3 abrasive exhibited the highest machining efficiency (MRR reaches 330.535 nm min−1) and better surface roughness (Ra reaches 22.741 nm). Excessive or insufficient bonding agent in CCAC will affect the processing performance of the abrasive. When the proportion of binding agent in the abrasive is 25%, CCAC has better processing ability and can realize efficient polishing of SiC wafers.

A distinctive material removal mechanism in the diamond grinding of (0001)-oriented single crystal gallium nitride and its implications in substrate manufacturing of brittle materials

Single crystal gallium nitride (GaN) substrates are highly demanded for fabricating advanced optoelectronic devices. It is thus essential to develop high efficiency machining technologies for this difficult-to-machine material, which in turn necessitates a thorough understanding of its deformation mechanism. In this study, the deformation and removal characteristics of (0001)-oriented single crystal GaN involved in diamond grinding were systematically investigated. The material removal exhibited a brittle mode when using relatively coarse diamond abrasives of 2000 in mesh size, while ductile removal was achieved when diamond abrasives of 6000 in mesh size were utilized. A novel peeling phenomenon was observed along (0001) lattice plane (c-plane) in the coarse grinding, as the crystal has a hexagonal crystal structure with c-planes serving as the preferable slip/cracking planes. Peeling observed in material removal agrees well with the findings that lateral planar defects were prone to initiate in nanoscratching in comparison to nanoindentation in the ductile regime, indicating that the effect of tangential grinding force is significant. The application of Molecular dynamics (MD) simulations, employing smaller indentation/scratching models, provided additional confirmation of the crucial role played by lateral force in initiating planar defects on c-planes. Furthermore, larger-scale MD scratching models substantiated the occurrence of peeling in the deformation process on c-plane, a finding corroborated by scratching experiments conducted in the brittle regime. Conversely, such peeling is absent on m- and a- planes. Complementary to the simulations, specifically designed grinding experiments were conducted to empirically demonstrate that peeling phenomena were intensified with elevated rotational wheel speeds. This enhancement was attributed to the increased tangential grinding force associated with higher speeds. These findings contribute to a comprehensive understanding of the intricate relationship between rotational wheel speed, tangential grinding force, and the observed peeling mechanisms in the context of single crystal GaN machining.

Investigating a novel and highly efficient approach for the fabrication of diamond profile rollers using Wire Electrical Discharge Conditioning (WEDC)

The fabrication of high-precision and high-performance profile rollers represents the main challenge of utilizing profile rollers as dressers to condition conventional grinding wheels. This results in high demands for an efficient process to manufacture profile rollers (form dressing wheels). Conventionally, diamond profile rollers have been produced through infiltration or negative electroplating methods. Nevertheless, these manufacturing methods suffer significant drawbacks, including extended production times and substantial costs. This study presents an innovative approach to fabricating diamond profile rollers using Wire Electrical Discharge Conditioning (WEDC). The WED-Conditioning emerges as an effective alternative to profile metal-bonded rotary diamond dressing tools. This innovative method leads to the production of diamond profile rollers in significantly shorter timeframes and at a more economical cost compared to the conventional manufacturing method with comparable quality. The research delves into the influence of profile roller specifications and conditioning strategies on the achievable profile accuracy and topography of the profile rollers. Also, the wear behavior of the WEDC-conditioned profile roller over long-term conditioning of conventional grinding wheels was studied. The findings highlight the significant contribution of the appropriate selection of WEDC strategies to the profile accuracy, with the potential to achieve profile accuracies comparable with conventional profile rollers. As well, grain size emerges as the primary determinant of achievable profile accuracy for profile rollers. The findings of this study could provide insights into optimizing the manufacturing process for super abrasive diamond profile rollers, thereby enabling their widespread use in the grinding industry.

Balling behavior and diamond graphitization of metal-matrix diamond composites by selective laser melting: A quantitative investigation

Selective laser melting (SLM) is an effective and potential technology to prepare metal-matrix diamond composites (MDC). In this study, balling phenomenon and graphitization of diamond of CuSn10-diamond composites by SLM were investigated. By univariate analysis of laser power and scanning speed on the morphology of single track, the balling phenomenon is directly affected by the flowability and wettability of the molten pool. By introducing the concept of laser energy density, balling and diamond graphitization are quantitatively evaluated by the standard deviation σ of surface balling height and IG: ID value, respectively. Balling degree increases with laser energy density, but diamond-graphitization turns out to be the opposite. The CuSn10-diamond composites with low balling and no diamond-graphitization can be obtained at moderate laser energy density of 0.17 J/mm. In terms of performances, bending strength is mainly affected the defects caused by balling, and wear properties is determined by the graphitization of diamond abrasives. Graphitization of diamond results in the transformation of wear mechanism from abrasive to adhesive wear. The optimal properties of 185.36 MPa in bending strength, 0.41 in coefficient of friction and minimum wear loss is obtained in the composite sample prepared at 0.17 J/mm.

The effect of diamond grain size on the formability and mechanical property of 3D-printed diamond tool

Because of the flexibility of structure design and material design, 3D-printed metal-bonded diamond tool is expected to be the next generation of diamond tools. In this paper, the selective laser melting process is utilized to fabricate the metal-bonded diamond tool based on the mixed powders consisted of AlSi10Mg powder and diamond powder. Relative density, material characterization and mechanical property are measured to figure out the effect of diamond grain size on the formability and property of 3D-printed diamond tool with diamond grain size from 200 mesh to 500 mesh. The results suggest that, when the diamond volume fraction stays the same, with the diamond grain size decreasing, the relative density and main mechanical properties descend due to the increment of defects. Furthermore, the 3D-printed diamond tool with evenly distributed and firmly embedded diamond abrasives can be fabricated and corresponding mechanical properties can meet the requirement of diamond tool.

Analysis of Subsurface Damage Structures of Gallium Nitride Substrates Induced by Mechanical Polishing with Diamond Abrasives

Subsurface damage (SSD) structures induced by mechanical polishing of gallium nitride (GaN) substrates are comprehensively investigated using atomic force microscopy, cathodoluminescence (CL) imaging, and cross‐sectional transmittance electron microscopy. The low removal rate of the CMP process is a barrier to high productivity of a GaN wafering process; therefore, reducing the chemical mechanical polishing (CMP) process time by reducing the depth of SSD induced by mechanical processing is an active research area. To better understand the SSD structures, the surface roughness, SSD depth, and SSD distributions induced by mechanical polishing are quantitatively evaluated in this study. The SSD structures induced by mechanical polishing can be quantitatively exhibited as the SSD distribution with the damage strength at the outermost surface and the damage propagation, which are obtained by CMP process time‐resolved CL imaging method. On the basis of the analysis results, a schematic model of the SSD structures for mechanically polished GaN substrates is proposed.

Investigation of Single Grain Grinding of Titanium Alloy Using Diamond Abrasive Grain with Positive Rake Angle

Traditional grinding, which is predominantly performed with a negative rake angle (NRA), can be transformed into grinding with a positive rake angle (PRA) by employing femtosecond pulsed laser technology to modify the apex angle of the grains to be less than 90°. This innovative approach aims to reduce grinding forces and grinding temperatures while improving the surface quality of typical hard-to-machine materials. To assess the performance of PRA single grain grinding and to investigate the underlying mechanisms, the finite element simulation software ABAQUS 6.14 was employed to model the grinding of Ti6Al4V titanium alloy with a single diamond abrasive grain. The dependence of grinding force and temperature in single grain grinding with a PRA or an NRA under different grinding parameters was studied and compared. PRA and NRA single diamond grain grinding experiments on Ti6Al4V alloy were carried out, with grinding forces measured using a dynamometer and compared with the simulation results. The grinding surface morphology and surface roughness were observed and measured, and a comparison was made between PRA and NRA grinding. The results indicated that in single diamond grain grinding, transforming to a PRA significantly enhances grinding performance, as evidenced by reduced grinding forces, lower temperatures, improved surface morphology, and decreased surface roughness. These findings suggest that PRA single diamond grain grinding offers substantial benefits for the precision machining of hard-to-machine materials, marking a step forward in optimizing surface finishes.

High-temperature tribological properties and wear mechanisms of multilayered cubic-BN/nanocrystalline diamond tool coatings

Wear failure of cutting inserts is the main form of failure that occurs when cutting difficult-to-machine materials at high speeds. To obtain cutting inserts with outstanding tribological properties, multilayered cubic boron nitride (cBN) and nanocrystalline diamond (NCD) coatings (cBN/NCD) were prepared on WC-6 wt% Co tool substrates. The tribological properties of the multilayered cBN/NCD coatings were studied at different temperatures, and the results showed that the coefficient of friction (COF) and wear rate of the coatings were closely interrelated to the temperatures, and the COF gradually decrease and the wear rate gradually increase as the temperature increased from room temperature (25 °C) to 600 °C. The COF and wear rate of the multilayer coatings at 600 °C were ∼0.05 and 8.43 × 10−6 mm3/(N⋅m), respectively. The wear resistance of the cBN/NCD coatings was higher than that of TiAlN coatings and PcBN tool materials by more than 3 and 4.5 times, respectively. The high-temperature wear failure modes of the multilayered cBN/NCD coatings were abrasive wear, diamond graphitization, and BN hydrolysis. Coating wear accelerated when pores were formed on the cBN surface of a multilayered cBN/NCD coating due to the low nucleation density of diamond. These results would guide the application of cBN/NCD-coated cutting tools in high-speed cutting processes.

Lapping performance of agglomerated diamond abrasives and analysis of sapphire processing process

Agglomerated Diamond (AD) abrasives were prepared using a ceramic bond and microfine single-crystal diamond (SCD). Lapping experiments were conducted to investigate the lapping performance and wear mechanisms of AD abrasives. The processing mechanisms of AD abrasives on sapphire wafers were revealed through friction and wear experiments and Power Spectral Density (PSD) methods. The results show that compared to W3 SCD, the material removal rate (MRR) of AD abrasives increased by 89.1 %, while the surface quality of the processed sapphire wafers was similar. Under the polyurethane lapping discs, AD abrasives achieved an MRR of 3.62 μm/min and a surface roughness (Ra) of 15.3 nm. The sapphire surface lapped with AD abrasives was the smoothest, with the PSD curve of the surface profile showing less noticeable layering, and the PSD values of the surface profile in the same frequency domain space were relatively the lowest. During the lapping process, the wear mechanisms of AD abrasives were identified as abrasive wear and micro-fracture. Under the impact and compression between the workpiece and the lapping discs, the fine SCD particles on the surface of the abrasives would wear and detach, and the network structure of the ceramic bond would fracture, exposing the fine SCD particles embedded in the bond to the surface, thus renewing and self-sharpening the cutting edges.

Photocatalytic assisted chemical mechanical polishing for silicon carbide using developed ceria coated diamond core-shell abrasives

The practical application of current photocatalytic-assisted chemical mechanical polishing (PCMP) technology still faces some challenges and difficulties, such as complex preparation process of abrasives, chemical failure, and the use of toxic chemicals. Herein, novel CeO2-coated diamond core/shell structure abrasives were successfully synthesized using a chemical precipitation method and applied in SiC-PCMP. After coating CeO2 on the surface of the diamond, the materials removal rate (MRR) was 56 % higher than that of the diamond abrasives. With ultraviolet (UV) irradiation, the MRR of CeO2/diamond abrasives (11.5 nm/min) increased by about 195 % compared with CeO2/diamond composite abrasives without UV. High surface quality (Ra: 0.4 nm) of the SiC substrate was obtained under UV light irradiation. The materials removal mechanism of SiC-PCMP was proposed.

Characterization of Polish-Induced Gouges on Single Crystal Sapphire Substrates

Single-crystal sapphire is known to be among the hardest insulators. Its mechanical properties and chemical inertness make it a challenging material to polish for the atomic-level surface smoothness required for its applications. Mechanical polish with diamond abrasives renders high removal rates but creates unacceptable levels of polish-induced gouges. Chemical mechanical polish on the other hand results in atomic smoothness but is a slow process. Hence, a combination of the two is used in the industry. In this work, we have attempted to characterize gouging and subsurface damage using atomic force microscopy, X-ray diffraction, and cross-section transmission electron microscopy on C-plane and A-plane sapphire induced by diamond abrasive mechanical polish and chemical mechanical polish with colloidal silica.

Mechanisms and characterization of a novel hybrid laser-enhanced particle laden electrochemical fabrication process for high quality micro-dimples on germanium wafers

The first-generation semiconductor materials represented by silicon (Si) and germanium (Ge) still hold a dominant position in many fields, including micro-electromechanical systems (MEMS) and integrated circuits (ICs). The processing of these materials continues to attract significant research attention for improvements in quality and efficiency. This study proposes a novel hybrid laser-enhanced particle-laden electrochemical machining (LEPL-ECM) process, whereby pulsed laser irradiation is utilized to selectively and locally enhance the electrical conductivity of Ge at specific locations. A neutral electrolyte jet, containing abrasive diamond particles, is applied to the location on the wafer surface opposite the laser irradiation, facilitating a localized and enhanced electrochemical dissolution. The effect of micro-particle erosion effectively removes the generated oxides and potential passivation layers, ensuring continuous and efficient electrochemical reactions. Consequently, high-quality micro-dimples with an entrance diameter of about 380–800 μm, a depth of around 138–300 μm, and a quasi-mirror surface with the roughness (Sa) of as low as 59.8 nm can be achieved within 90 s. Furthermore, the effects of the applied voltage, laser power and processing time on the resulting dimple characteristics and surface quality are discussed, along with a detailed morphology characterization. Dense micro-pits, radial streamlined micro-grooves and a special transitional region have been observed on dimple center, sidewall and near the edge, respectively, and the formation mechanism have been analyzed. Finally, a simulation of the electrolyte jet induced fluid pressure and velocity as well as the particle trajectory and distributions within and surrounding the dimple structure was conducted, which reveals that the synergistic mechanism associated with the hybrid material removal process involves both electrochemical corrosion and abrasive erosion.

Effect of Surface Structure on the Sensitivity of Fluorescence-Enhanced Si Photodiodes for Ultraviolet C Light Measurement

This study aims to significantly enhance the sensitivity of a fluorescence-enhanced Si photodiode (FE-PD) to ultraviolet C-ray (UVC) light by optimizing the three-dimensional surface shape of the phosphor attached to the Si-PD, thereby increasing the UVC detection sensitivity. In the sensitivity-enhanced FE-PD, the surface of the red fluorescent acrylic resin phosphor affixed to the Si-PD was carved with a stripe and grid at varying depths, and triangular roofs and square pyramids at various angles. The effects of roughening the phosphor surfaces with diamond abrasives of varying mesh sizes—ranging from #180 to #3000—were comparatively evaluated against those with flat, mirror-like surfaces. As observed, the UVC light sensitivity of the FE-PD using a surface-carved triangular roofs and square pyramids at angle of 70° exhibited significant improvements compared to the Si-PD with both non-modified and mirror-polished phosphors. Thus, the FE-PD with a surface-modified phosphor is a promising candidate for UVC light sensor.

Modeling the wear of the "diamond-containing mineral ceramics — ceramics" friction pair

Based on the solution of the contact mechanics problem, a model of wear of the "diamond-containing mineral ceramics — ceramics" friction pair is constructed, in which diamond grains in the ceramic matrix are represented as spherical segments of the same radius. The law of distribution of diamond grains in a ceramic matrix is power law. The dependences of grinding productivity and wear rate of diamond-containing tools on the physical and mechanical properties of contacting materials, roughness parameters of friction surfaces and loading conditions are obtained. Keywords:abrasive diamond tools, mineral ceramics, ceramics, contact interaction model, productivity, grinding, wear onvk@mail.ru, alnikbltov@rambler.ru, vnvkv@yandex.ru