Residual Particles Research Articles

Cortical Versus Cancellous Solvent-Dehydrated Bone Allograft for Alveolar Ridge Preservation: A Histologic Study.

Allografts have been routinely used for immediate grafting of extraction sites as modalities of alveolar ridge preservation (ARP). Solvent-dehydrated bone allograft (SDBA), which is commonly utilized for socket grafting, exists in the form of cortical and cancellous particles. This study aims to provide a histologic comparison of cortical and cancellous SDBA for ARP. A total of 35 extraction sockets were allocated to receive either a cortical (17 sites) or cancellous (18 sites) SDBA, followed by application of a resorbable collagen wound dressing in both groups. At approximately 4 months, a bone core biopsy sample was obtained during implant placement. Histomorphometric assessment was then conducted to compare the differences between both forms of SDBA. Within its limitations, a higher percentage of vital bone was observed in the cortical bone group compared to the cancellous bone group (28.6% vs 20.1%, respectively, P = .042), while there was a lack of statistically significant differences among other fractions of the bone biopsy sample (residual graft particles and nonmineralized tissues such as connective tissue or other components).

Dissolution Profiles of Carbamazepine Cocrystals with Cis-Trans Isomeric Coformers.

The purpose of the present study was to investigate the dissolution profiles of cocrystals with cis-trans isomeric coformers. Previously, the carbamazepine (CBZ) cocrystals with even-carbon dicarboxylic acids showed higher supersaturation than those with odd-carbon ones, attributed to particle surface solution-mediated phase transformation (PS-SMPT) to CBZ dihydrate (CBZ DH). However, it has been unknown whether this odd-even pattern holds for cis-trans isomeric coformers. CBZ cocrystals with maleic acid (MLE) and fumaric acid (FUM) (CBZ-FUM anhydrate (CBZ-FUM AH) and monohydrate (CBZ-FUM H2O)) were employed as model cocrystals. Hydroxypropyl methylcellulose (HPMC), polyvinylpyrrolidone, and polyethylene glycol 6000 (PEG) were used as precipitation inhibitors. Dissolution tests were performed under a non-sink condition. Residual particles were analyzed by powder X-ray diffraction, differential scanning calorimetry, polarized light microscope, and scanning electron microscope. All cocrystals showed little supersaturation in the absence of a polymer. In 0.1% HPMC, CBZ-FUM AH showed significant supersaturation, whereas CBZ-MLE and CBZ-FUM H2O did not for the first two hours. HPMC reduced the initial dissolution rate of CBZ-MLE and CBZ-FUM H2O while inducing the highest supersaturation among the polymers after 96h. The particle surface changed from a smooth plane to a striped pattern, but little or no CBZ DH was detected. The cocrystals with cis-trans isomeric coformers showed different dissolution profiles. HPMC increased the dissolution rate of CBZ-FUM AH by inhibiting PS-SMPT but reduced the dissolution rate of CBZ-MLE and CBZ-FUM H2O without inducing PS-SMPT. The striped pattern was suggested to be due to surface etching rather than PS-SMPT.

Performance of eco‐friendly particleboard from agro‐industrial residues bonded with formaldehyde‐free natural rubber latex adhesive for interior applications

AbstractIn this work, a novel way is proposed to produce an eco‐friendly and formaldehyde‐free particleboard (PB) panel from agro‐industrial residues bonded with natural rubber latex (NRL)‐based adhesive. Polyvinyl alcohol (PVOH) was added as an adhesion promoter and polymeric 4,4‐methylene diphenyl diisocyanate (pMDI) was used as cross‐linker. Different formulations of agro‐industrial residues (cassava stem, sengon wood waste, and rice husk) and different contents of NRL‐adhesive (10%, 15%, and 20%) were applied to prepare the PB panel. Several techniques were performed to characterize the properties of NRL‐based adhesive and to evaluate the performance of PB panels from agro‐industrial residues bonded with NRL‐based adhesive. The blending of NRL and PVOH resulted in weak hydrogen bonds in the polymer blends. Incorporation of pMDI provided NCO groups as the reactive site for cross‐linking with NRL‐PVOH via urethane linkages. The results showed that no remarkable differences in the physical properties of the PB panel, such as density, moisture content, water absorption, and thickness swelling, with different agro‐industrial residues formulations and NRL‐adhesive content. By contrast, greater NRL‐adhesive content affected the mechanical properties of the PB panel. The best mechanical properties of the PB panel were obtained using a formulation of 40% of cassava stem, 30% of sengon wood waste, 30% of rice husk, and bonded with 20% of NRL‐adhesive content, which resulted in 4.02 MPa of modulus of rupture (MOR), 441.00 MPa of modulus of elasticity (MOE), and 0.19 MPa of internal bonding (IB) strength. A combination of agro‐industrial residues particles and NRL‐based adhesive presented a high potential for application as an eco‐friendly, formaldehyde‐free, and non‐structural PB such as interior applications.

Red Ghost Image Elimination Method Based on Driving Waveform Design in Three-Color Electrophoretic Displays.

Three-color electrophoretic displays (EPDs) are a new type of optoelectronic display device. However, they have the defect of red ghost images during gray scale transformation, which affects the accuracy of the gray scale display. In this paper, we proposed a new driving method for eliminating the red ghost images. A driving waveform was composed of an erasing stage, an activation stage, and a driving stage. First, the erasing stage was subdivided into a red erasing stage and an original erasing stage, the red erasing stage was used to eliminate residual red particles in the top of the microcapsules. Then, a high-frequency square wave was used as the activation stage for increasing the activity of the black and white particles. Meanwhile, the intensity of flickers could be decreased by the high-frequency square wave. Finally, the performance of the driving waveform was tested by a colorimeter. The experimental results showed that the driving waveform could effectively eliminate red ghost images by 80.43% and reduce the flicker intensity by 79.63%, compared with an existing driving waveform.

Control of the Micro-Defects on the Surface of Silicon Wafer in Chemical Mechanical Polishing

The final polishing of silicon results in the irresistible formation of micro-defects (i.e., particle residues and scratches) on the surface. In view of this problem, the synergistic effect of surfactants and water-soluble polymers in inhibiting the micro-defects on the silicon surface was studied in this paper to improve the wettability of the slurry and reduce the micro-flocculation of abrasive particles. The results showed that the total number of residual particles (≥0.06 μm) on the polished surface was reduced from 24,784 to 277 with the adsorption of cationic polyacrylamide (CPAM) and fatty alcohol polyoxyethylene ether (AEO-9). The water-soluble polyvinylpyrrolidone (PVP) polymer could coat on the SiO2 abrasives, inhibit the flocculation of abrasive particles, avoid scratches on the silicon surface and further reduce the number of residual particles (≥0.06 μm) to 67 on the polished surface. Furthermore, a contact angle analyzer was used to characterize the wettability of the components in the slurry, and a large particle counter was used to analyze the changes in the number of large particles in the slurry component. Finally, a mechanism of surfactants and a water-soluble polymer combined system was proposed to suppress the micro-defects on the surface of the silicon wafer.

Asynchronous Synergistic Damage Effect of Atomic Oxygen and Space Micro Debris on Kapton Film

In the low earth orbit environment, many environmental factors lead to the degradation of material properties. The synergistic effect of long-term atomic oxygen (AO) irradiation and instantaneous impact of micro debris (MD) on long-term and transient space environmental factors has attracted more and more attention. In this paper, the performance evolution of Kapton films under the conditions of MD, AO single factor load spectrum and MD + AO, AO + MD asynchronous synergistic load spectrum were studied by laser driven flyer and microwave atomic oxygen technology. The macro morphology, optical properties and quality changes of Kapton films before and after each load spectrum were compared, and the mechanism of micro morphology and structure changes was explored. The results show that compared with MD + AO loading spectrum, the surface holes of Kapton films are larger under AO + MD load spectrum condition, the residual aluminum particles formed by reverse sputtering of Al particles during impact are less, the average transmittance of the film decreases slightly, and the weight loss of Kapton film is slightly more under the same atomic oxygen exposure time. Under the condition of MD + AO load spectrum, plastic tearing cracks, craters and holes are formed on the surface of Kapton film; the edge of the hole formed under the condition of AO + MD load spectrum is straight, without obvious depression and tear characteristics. Under the condition of MD + AO load spectrum, due to the adhesion of Al after the impact of micro debris, the subsequent atomic oxygen erosion of the film is reduced, so the C-C bond is not seriously damaged, and a considerable part of the residual aluminum flyer is oxidized to alumina by atomic oxygen; The AO + MD loading spectrum test makes the film first eroded by atomic oxygen, resulting in the reduction in C–O bond and C–C bond. The fracture of C–N bond is caused by the hypervelocity impact of micro debris. Hypervelocity impact leads to the thermal decomposition of the material, destroys the C–N bond in the imide ring and generates an N–H bond. This study will provide a method reference and a reference for the multi-factor ground collaborative simulation of space environment of spacecraft materials.

Selective electrochemical deposition of indium in-between silicon nanowire arrays fabricated by metal-assisted chemical etching

Indium electrodeposition in-between silicon nanowire arrays fabricated by silver-assisted chemical etching of lightly-doped (100)-oriented silicon wafers is evaluated. It is concluded based on SEM and EDX analysis of indium's distribution that, by utilizing pulsed-mode electrodeposition and maintaining a sufficiently low duty cycle value, indium particles can be formed exclusively at the very bottom of each consecutive pore on the residual silver particles left over from metal-assisted etching. This result differs significantly from irregular pore filling along with surface and subsurface deposition observed in the cases of continuous galvanostatic deposition regimes at prolonged durations or in the absence of residual silver particles. Bottommost fusible metal deposit localization, which is unattainable on porous silicon fabricated by electrochemical anodization, is presumed to be optimal for the growth of germanium crystallites inside the pores via the electrochemical liquid-liquid-solid approach and subsequent silicon-germanium alloy formation through thermal annealing.

Formation mechanism for the white etching microstructure in the subsurface of the failure pearlite wheel steel

The subsurface white etching microstructure (WEM) was an important reason to cause the rolling contact fatigue (RCF) failure of wheel materials. The WEM formation mechanism in the subsurface layers of failed pearlite steel wheel was analyzed by using a scanning electron microscope, transmission electron microscope, and nanoindenter. The results showed that RCF cracks were mostly at the interface between the WEM and pearlite matrix. A large amount of the WEM was found in areas with no RCF cracks. This indicates that the WEM was formed prior to the RCF cracks. The WEM was comprised of nanostructured ferrite grains and residual cementite particles, and its hardness (approximately 920 HV) was about 3 times as high as that of the pearlite matrix. A soft area model for WEM formation is proposed based on the microstructural characteristics of two types of ferrite grains and the dissolution of cementite in pearlite resulting from continuous plastic deformation. During the wheel–rail contact, continuous plastic deformation in the subsurface under high contact stress conditions causes the successive refinement of the proeutectoid ferrite (PF) with low strength and ferrite grains in pearlite, the dissolution of cementite, and the improvement in the corrosion resistance, which cause the WEM to look white under an optical microscope. The WEM formation processes induced by alternating fatigue load were similar to that of surface nanocrystallization through surface mechanical attrition treatment. The great difference between the WEM and the pearlite matrix in the strength results in the crack propagating along their interface, therefore the nonuniform distribution of the WEM along both edges of RCF cracks was found commonly.

Residual sand particles as a cause of chipping of ceramic cladding

Residual sand particles as a cause of chipping of ceramic cladding

Formação óssea em levantamento de seio maxilar com diferentes tamanhos de partículas de enxerto xenográfico: revisão sistemática e meta-análise

ABSTRACT The commercial bovine bone mineral most commonly used is available in two particle sizes and studies have demonstrated contradictory results regarding bone formation volume using small or large particles. The aim of this systematic review and meta-analysis was to compare the bone formation volume and residual bovine bone volume in sinus floor augmentation using small and large particles. The following outcome measures were assessed: bone formation volume (%) and residual bovine bone particles volume (%) assessed by histomorphometric analysis. The initial screening resulted in 236 records. After removal of duplicated articles and analysis of titles, abstracts and full texts, three articles were included in the meta-analysis. The bone formation volume and residual bovine bone volume did not differ between small and large particles, with low heterogeneity of studies. The particle size of bovine bone mineral did not influence bone formation percentage; small and large particles of bovine bone graft presented similar residual bone mineral; more randomized clinical trials should be performed to completely confirm that bovine bone mineral particle size does not affect the result of sinus floor augmentation.

Effects of Residual Stress and Intragranular Particles on Mechanical Properties of Hot-Pressed Al2o3/Sic Ceramic Composites

Effects of Residual Stress and Intragranular Particles on Mechanical Properties of Hot-Pressed Al2o3/Sic Ceramic Composites

Preclinical bioequivalence study of E.coli-derived rhBMP-2/β-TCP and autogenous bone in a canine guided-bone regeneration model.

Bone morphogenetic protein (BMP)-2 is a potent growth factor that is widely used in the orthopedic and dental fields for bone regeneration. However, recombinant human BMP-2 (rhBMP-2) products have not been legally approved in Japan. Recently, our research group succeeded in producing GMP-grade rhBMP-2 using the E. coli system (E-rhBMP-2) at the industrial level and developed E-rhBMP-2 adsorbed onto β-TCP (E-rhBMP-2/β-TCP) as an alternative material to autogenous bone grafts. Previous studies on the toxicity, pharmacokinetics, and optimal doses of E-rhBMP-2 have confirmed its safety and efficiency. However, comparative studies with standard treatment therapies are still necessary before clinical application in humans. Therefore, in this preclinical study, we compared the bone regeneration ability of E-rhBMP-2/β-TCP and autogenous bone grafts in a canine guided-bone regeneration model. Following extraction of the maxillary third premolar, box-type bone defects (10 mmL × 4 mmW × 9 mmH) were created in the extraction socket area and transplanted with E-rhBMP-2/β-TCP or autogenous bone graft in a canine. After 8 weeks, micro-CT and histological analyses were performed. Transplantation of both E-rhBMP-2/β-TCP and autogenous bone graft significantly promoted bone formation compared to the non-transplantation control group. The bone formation ability of E-rhBMP-2/β-TCP was equal to that of the autogenous bone graft. Histological analysis showed that excessive infiltration of inflammatory cells and residual β-TCP particles mostly were not observed in the E-rhBMP-2/β-TCP transplantation group. This preclinical study demonstrated that E-rhBMP-2/β-TCP and autogenous bone have equal potential to promote bone regeneration.

Evaluation of regeneration after the application of 2 types of deproteinized bovine bone mineral to alveolar bone defects in adult dogs.

The aim of this study was to evaluate the preclinical results of 2 types of commercially available deproteinized bovine bone mineral (DBBM) when applied to alveolar bone defects in dogs. This study was conducted using 6 beagles. Alveolar defects in the mandible were formed and filled with 2 DBBMs produced by a similar procedure. Defects were randomly assigned to be filled using DBBM 1 or 2. All defects were covered with a collagen membrane and had a healing period of 12 weeks. After the dogs were sacrificed, histological, histomorphometric, and linear/volumetric analyses were performed. Both DBBM groups showed similar histological findings, demonstrating that bone remodeling had occurred and new bone had formed. The residual bone particles were surrounded by newly formed vital bone. In the histomorphometric analysis, the ratio of the area of vital bone and residual bone substitute in DBBM 2 (38.18% and 3.47%, respectively) was higher than that of DBBM 1 (33.74% and 3.41%, respectively), although the difference was not statistically significant. There were also no statistically significant differences between both groups in linear and volumetric analyses using micro-computed tomography scans and digitized images of dental casts. In the present study, DBBM 1and 2, which were produced by similar processes, showed similar results in histological, histomorphometric, and volumetric analyses. Further studies are needed to identify more specific differences between the 2 DBBMs.

Improvement of the mechanical properties of PLA/coffee residue biocomposites from the liquor industry

This work deals with the revaluation of coffee bean residues from the coffee liquor industry with the aim of developing eco-efficient composite materials with a polymeric matrix of polylactic acid (PLA). The coffee residue is incorporated in a proportion of 20% to the PLA by extrusion. After a grinding process, they are processed by injection to obtain standardized test pieces for their characterization. In order to improve the mechanical properties, as well as the toughness and compatibility between the biopolyester and the lignocellulosic particles of the coffee residue, two oligomers of lactic acid (OLA2 and OLA2mal functionalized with maleic anhydride) are added, together with the particles of the coffee residue during the extrusion process. These "Green composites" show that the incorporation of coffee residue particles from the manufacture of coffee liquor considerably increases the ductility of the samples analyzed by practically 280% due to their high content of oils present in the lignocellulosic residue. In addition, the incorporation of the OLA2 and OLA2mal oligomers contribute to improve the tensile strength of the composite materials studied, by 35% and 60%, respectively. These interesting results show the wide possibilities of this eco-efficient and sustainable material made of PLA and coffee residue. These are biodegradable materials, respectful of the environment and that allow the revaluation of coffee bean residues from the agri-food industry such as coffee liquor.

Extraction method development for nanoplastics from oyster and fish tissues

Nanoplastics are now found in some environmental media and consumer products. However, very limited data on nanoplastics are available for one of the main human consumption sources of microplastics: seafood. Unlike microplastics, a method for extracting nanoplastics from seafood is still lacking. Herein, a combination of common extraction techniques including enzymatic digestion, sequential membrane filtration, centrifugal concentration, and purification (dialysis and sodium dodecylsulfate (SDS) incubation), was developed to extract nanoplastics from oyster and fish tissues. Corolase with subsequent lipase treatment achieved the highest digestion efficiencies (88– 89%) for non-homogenized tissues compared to other proteases and additional cellulase or H2O2 treatment. With the exception of polyethylene terephthalate (PET), enzymatic digestion did not change the morphology or structure of polyvinyl chloride (PVC), polyethylene (PE), or polystyrene (PS) nanoplastic particles, and the subsequent extraction procedures had good recoveries of 71– 110% for fluorescence-labeled 76-nm PVC and 100- and 750-nm PS, as validated by a Nanoparticle Tracking Analysis (NTA). Few of the 1011 digested residual particles of 150– 300 nm in diameter per oyster or per serving of fish tissue were left in the method blank. Consequently, this efficient approach could be used as a pretreatment protocol for current potential nanoplastic detection methods.

Development of a novel wet cleaning solution for Post-CMP SiO2 and Si3N4 films

After CMP, the removal of ceria nanoparticle residues is difficult due to the formation of Ce–O–Si chemical bonds on the SiO2 film surface. After STI CMP, several post-CMP cleaning processes are performed, including the application of PVA brushing and megasonic technologies using conventional cleaning solutions such as SC1, SC2, and SPM. However, more effective post-CMP cleaning technologies are still needed for the fabrication of advanced integrated circuit devices. In this study, we developed a novel post-CMP cleaning solution consisting of tetramethylammonium hydroxide (TMAH), ethylenediaminetetraacetic acid (EDTA), and Disponil to replace existing cleaning solutions. In its non-diluted form, this cleaning solution removed 99.5% of residual particles and 98.3% of ceria residue on an SiO2 film surface, as well as 98.5% of residual particles and 98.1% of ceria residue on an Si3N4 film surface, respectively. At 5 × dilution, it removed 97.8% of residual particles and 97.0% of ceria residue on the SiO2 film surface, as well as 97.8% of residual particles and 96.3% of ceria residue on the Si3N4 film surface, respectively. The effectiveness of this cleaning solution for residual ceria nanoparticles is highly comparable to SC1 and SPM conventional cleaning solutions, even though it is used at a relatively low temperature with less etching. Additionally, AFM of the surface topography showed fewer particles and better surface roughness compared with SC1 and SPM cleaning. Thus, this approach can be used to remove ceria nanoparticles from polished SiO2 and Si3N4 films through increased wettability, slight dissolving of the film, and extremely enhanced repulsive force.

The contribution of Saharan dust to the ice-nucleating particle concentrations at the High Altitude Station Jungfraujoch (3580 m a.s.l.), Switzerland

Abstract. The ice phase in mixed-phase clouds has a pivotal role in global precipitation formation as well as for Earth's radiative budget. Above 235 K, sparse particles with the special ability to initiate ice formation, ice-nucleating particles (INPs), are responsible for primary ice formation within these clouds. Mineral dust has been found to be one of the most abundant INPs in the atmosphere at temperatures colder than 258 K. However, the extent of the abundance and distribution of INPs remains largely unknown. To better constrain and quantify the impact of mineral dust on ice nucleation, we investigate the frequency of Saharan dust events (SDEs) and their contribution to the INP number concentration at 243 K and at a saturation ratio with respect to liquid water (Sw) of 1.04 at the High Altitude Research Station Jungfraujoch (JFJ; 3580 m a.s.l.) from February to December 2020. Using the single-scattering albedo Ångström exponent retrieved from a nephelometer and an Aethalometer, satellite-retrieved dust mass concentrations, simulated tropospheric residence times, and the attenuated backscatter signal from a ceilometer as proxies, we detected 26 SDEs, which in total contributed to 17 % of the time span analyzed. We found every SDE to show an increase in median INP concentrations compared to those of all non-SDE periods; however, they were not always statistically significant. Median INP concentrations of individual SDEs spread between 1.7 and 161 INP std L−1 and thus 2 orders of magnitude. In the entire period analyzed, 74.7 ± 0.2 % of all INPs were measured during SDEs. Based on satellite-retrieved dust mass concentrations, we argue that mineral dust is also present at JFJ outside of SDEs but at much lower concentrations, thus still contributing to the INP population. We estimate that 97 % of all INPs active in the immersion mode at 243 K and Sw=1.04 at JFJ are dust particles. Overall, we found INP number concentrations to follow a leptokurtic lognormal frequency distribution. We found the INP number concentrations during SDEs to correlate with the ceilometer backscatter signals from a ceilometer located 4.5 km north of JFJ and 1510 m lower in altitude, thus scanning the air masses at the same altitude as JFJ. Using the European ceilometer network allows us to study the atmospheric pathway of mineral dust plumes over a large domain, which we demonstrate in two case studies. These studies showed that mineral dust plumes form ice crystals at cirrus altitudes, which then sediment to lower altitudes. Upon sublimation in dryer air layers, the residual particles are left potentially pre-activated. Future improvements to the sampling lines of INP counters are required to study whether these particles are indeed pre-activated, leading to larger INP number concentrations than reported here.

Preliminary Evaluation of Gunshot Residue (GSR) Using 3-Aminophenol as a Substitute in Modified Griess Test

In forensic ballistics, gunshot residue (GSR) particles can be detected using screening or presumptive tests which are mainly focused on the chromophoric reaction. Most tests serve as an initial indication for a forensic investigator at the crime scene before instrumental analysis for definitive identification. The screening methods are known to be convenient, have fast analysis, and minimal preparation. In GSR analysis, the well-known method of detecting GSR known as the Modified Griess Test (MGT) requires acid and heat for the reaction. Therefore, this study demonstrated a new and rapid screening test named the Rapid Griess Test (RGT) for the detection of GSR. This study intends to improve the functionality of previous screening reagents in determining nitrite (NO2–), the composition present after shooting activity. To do this, chemical reagents with an amino group, 3-aminophenol, were substituted with alpha-naphthol. The experiment showed that the reactions were positive color changes using standard NO2– and real GSR samples. The diazotization reactions involving sulfanilic acid and 3-aminophenol produced azo dyes that changed the solution from colorless to orange in the presence of NO2–. The RGT reagent will make it possible to avoid using heat and the addition of acetic acids in a sample to form chromophoric reactions. Moreover, the colorimetric method using Video Spectral Comparator (VSC) showed that RGT had higher intensity of the orange color when compared to MGT.

VOC removal from ventilation air by gas-to-particle conversion: Towords the Enhancement of process efficiency

Volatile organic compounds (VOCs) form a broad group of airborne pollutants. They contribute to air pollution in various ways and thus should be removed from the air used in occupied spaces. This article presents an attempt to develop a gas-to-particle conversion process to clean VOCs from ventilation air. The prototype combines processes of plasmolysis, photolysis, particle growth, particle precipitation, and catalysis. The system was tested in laboratory environment against simulated polluted air with styrene, cyclohexane, hexane, and ethylacetate, at energy yields in range 0.31–1.90, g/kWh. Ozone was generated by non-thermal plasma (NTP) at a yield of 0.2–0.7 g/h. The power of NTP reactor (5–25 W) and air flow (25–150 m3/h) rate were the main variables of the experiment. Overall removal efficiency of pollutants was in range from 75.7 to 99.8%, The combination of plasmolysis and subsequent photolysis/bipolar ionization was proved as a technologically viable sequence for the gas-to-particle conversion and growth, resulting in particle number concentrations up to 3.9 × 107 p/cm3. The needle-to-plate type electrostatic precipitator (ESP) removal ratio as high as 99.99% providing residual particle concentrations to levels <104 p/cm3, while ozone has been destructed in ozone catalyst to the levels <127 μg/m3. The technology proves as a effective and energy efficient for the removal of VOCs from ventilation air.

Study on cutting performance of SiCp/Al composite using textured YG8 carbide tool

Precision machining of SiCp/Al composites is a challenge due to the existence of reinforcement phase in this material. This work focuses on the study of the textured tools’ cutting performance on SiCp/Al composite, as well as the comparison with non-textured tools. The results show that the micro-pit textured tool can reduce the cutting force by 5–13% and cutting length by 9–39%. Compared with non-textured tools, the cutting stability of the micro-pit textured tools is better. It is found that the surface roughness is the smallest (0.4 μm) when the texture spacing is 100 μm, and the residual stress can be minimized to around 15 MPa in the case of texture spacing 80 μm. In addition, the SiC particles with size of around 2–12 μm in the SiCp/Al composite may play a supporting role between the texture and the chips, which results in three-body friction, thereby reducing tool wear, sticking, and secondary cutting phenomenon. At the same time, some SiC particles enter into the micro-pit texture, so that the number of residual particles on the surface is reduced and the friction between the tool and the surface then decreases, which improves the surface roughness, and reduces the surface residual stress.