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[IEEE 2019 IEEE International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO) - Zhenjiang, China (2019.8.4-2019.8.8)] 2019 IEEE International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO) - Study on Laser-assisted Machining of Aluminum-based Silicon Carbide
摘要： In order to explore the feasibility of laser-assisted machining (LAM) in the field of metal matrix composites (MMCs), an orthogonal precision micro-cutting experiment of 45% volume fraction aluminum-based silicon carbide (SiCp/Al) was carried out, and the experimental results were analyzed and discussed. The experimental results show that laser-assisted processing can improve the processing characteristics of SiCp/Al materials. Under the appropriate laser power, the laser assisted processing technology can effectively improve the surface roughness of the workpiece to be processed, obtaining a high-quality surface finish, and increase the tool wear resistance to a certain extent at the same time. Laser assisted machining technology can be applied to the processing of metal matrix composites.
关键词： surface morphology,laser-assisted,SiCp/Al,tool wear,surface roughness
更新于2025-09-16 10:30:52
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Estimation of Optimal Laser Parameters On Inconel 718 By Taguchi Methodology
摘要： Inconel 718 is a representative of high temperature alloy which poses substantial difficulties in machining processes. High strength, high cutting temperature and a subsequent work hardening during machining process adversely affect the cutting force, surface integrity, tool life and chip breakability. The above difficulties have been disproving by employing the Laser Assisted Machining (LAM). LAM is a hybrid technique and used to machining the work-piece with conventional tool after softening it with laser emitted heat. An attempt has been made in the present study for an experimental investigation on the machining attributes of 718 Inconel super alloy during laser assisted machining using uncoated carbide insert. Experimental plan is designed based on Taguchi’s L18 mixed orthogonal array of design of experiment. Three response values such as cutting force, surface roughness and tool wear are measured and their effects are studied. The variability due to the machining parameters are dispensed using variance test. Predictive regression equations are developed for the estimation of all the quality characteristics. Also the Pearson correlation coefficient analysis is calculated to analyze the correlation between the input parameters and quality characteristics. Results showed a strong correlation between the feed rate and the cutting force and surface roughness followed by cutting speed. The results obtained from experiments are analyzed to predict the optimal machining conditions using desirability approach. At the optimal laser parameters, the tool life, when laser beam is used, is improved by 9% compared to conventional machining.
关键词： cutting forces,Taguchi method,surface roughness,tool wear,laser parameters
更新于2025-09-16 10:30:52
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A research on the surface morphology, microstructure evolution and wear property of selective laser melting Al <sub/>2</sub> O <sub/>3</sub> /P20 composites
摘要： The Al2O3/P20 composites were successfully manufactured by selective laser melting (SLM) from powder mixture of Al2O3 and P20 mold steel with different Al2O3 contents (0.5 wt%, 1 wt%, 2 wt%) in this work. The surface morphology analysis indicated that Al2O3 particles were partially or fully melted for agglomerates during the SLM process with segregating between contiguous molten tracks. The model of Al2O3 diffusing during the SLM process was built for illustrating the generated mechanism of Al2O3 agglomerates. Moreover, the densi?cation behavior of specimens became poor (the relative density declined from 99.3% to 94.2%) as the Al2O3 contents increased. The microstructure within samples had some obvious variations including coarsening martensite microstructure, tempering microstructure transformation, reverted austensite and precipitation of ?ne carbide particles. The result of Rockwll hardness test manifested that 1 wt% obtained the maximum value of 57.6 HRC, while 2 wt% had the minimum value of 45.9 HRC. Tribological test revealed that coef?cient of friction (COF) and wear rate signi?cantly declined when the Al2O3 contents were 1 wt% and 2 wt%, which emphasized the superior wear resistance property.
关键词： wear resistance,selective laser melting,Al2O3,P20 mold steel,microstructure,composite
更新于2025-09-16 10:30:52
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Novel Confocal-Laser-Scanning-Microscopy and conventional measures investigating eroded dentine following dentifrice dab-on and brushing abrasion
摘要： Objectives: To validate novel non-contacting Confocal-Laser-Scanning-Microscopy (CLSM) methodology with conventional Contacting Pro?lometry (CP) measures investigating brushing or dab-on of stannous-?uoride dentifrice on early aggressive dentine erosion. Methods: 75 polished human dentine samples were prepared and eroded in agitated 6% citric acid then randomly allocated into 5 intervention groups; arti?cial saliva control (1); controlled use of a pressure sensitive counter-rotating oscillatory powered toothbrush with sodium-?uoride NaF (2) or stannous-?uoride SnF2 (3), and dab-on application of NaF (4) or SnF2 (5). Samples underwent three cycles of intervention and 2-min agitated 6 % citric acid challenges. CLSM images were taken and 3D reconstructions produced of step height using a developed software algorithm. In addition, 20 % samples were randomised and pro?led using CP to measure step height and surface roughness. Vickers's diamond micro-hardness testing was carried out on all samples. Results: Comparing CLSM and CP; Pearson correlation was 0.77 and Intra-class correlation 0.81 (p ? 0.01). There were no signi?cant statistical differences in step height between groups using both CLSM and CP. From baseline, SnF2 brushing (3) increased micro-hardness more than control (1) (p ? 0.03), NaF (4) and SnF2 dab-on (5) (p (cid:2) 0.001), and increased surface roughness more than control (p ? 0.02), NaF brushing (2) and NaF dab-on (4) (p (cid:2) 0.017). Dab-on of SnF2 (5) produced rougher surfaces than control (1) (p ? 0.014) and reduced hardness compared with NaF brushing (p ? 0.04). Conclusions: Good agreement and correlation exists between CLSM and CP measures in dentine. There were no signi?cant differences in surface loss after interventions between groups. Compared with control, SnF2 application increased dentine surface roughness and SnF2 controlled powered brushing application increased dentine hardness, likely caused by exposure of uneroded dentine. Clinical signi?cance: Isosurfaces produced using CLSM can be used to represent dentine step height loss. They show good correlation and agreement with conventional CP measures, following early aggressive erosion-abrasion cycles of dentine. The CLSM and computer algorithm therefore provides an accurate, standalone and non-contacting three-dimensional measurement of early dentine wear. Stannous-?uoride brushing, and dab-on application offer no bene?ts following early aggressive erosion in dentine. To reduce dentine wear, limiting erosive challenges and avoiding brushing post-erosion is advised.
关键词： Prosthetic dentistry,Medical imaging,Dab-on,Mathematical biosciences,Dental materials,Biophysics,Dentistry,Erosion,Measurement,Software engineering,Applied computing in medical science,Abrasion,Dentifrice,Biocomputational method,Dentine-wear
更新于2025-09-16 10:30:52
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Wear Tribo-Performances of Laser Cladding Colmonoy-6 and Stellite-6 Micron Layers on Stainless Steel 304 Using Yb:YAG Disk Laser
摘要： Stainless steel material has been widely used in aeronautical, chemical and nuclear industries due to good corrosion resistance. However, the material has less hardness and wear resistance. In this study, two various depositions namely Colmonoy-6 and Stellite-6 have produced on 304 Stainless steel. Besides, the coating was examined to reveal their metallurgical, mechanical and tribological properties. In addition, wear mechanism, wear debris and roughness averages were studied. The outcomes indicate that both coatings show with dendrite structure due to rapid cooling rates. Hardness of the clad surface has improved than substrate material. The results of friction coefficient of specimen with Colmonoy-6 is lower than that of specimens Stellite-6 and substrate. Also, wear resistance of Colmonoy-6 has increased 49 times than substrate sample, which reveals that Colmonoy-6 laser cladding plays role on wear resistance. Adhesive and abrasive are the major wear mechanisms in the present study.
关键词： Wear debris,Microstructure,Stainless steel 304,Roughness,Wear performance,XRD,Laser cladding,Hardness
更新于2025-09-12 10:27:22
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Improving impact wear resistance of Ti-6Al-4V alloy treated by laser shock peening
摘要： The effects of laser shock peening (LSP) on the impact wear behavior of Ti?6Al?4V alloys were investigated by a homemade impact wear test rig. The microstructure and mechanical properties of the peened samples were studied. During the impact wear test, the energy absorption, impact force, wear contact time and wear mechanism of all the test samples were investigated in terms of the influence of the impact kinetic energy. The results showed that microhardness, elastic modulus and residual compressive stress of the treated samples were markedly improved. The wear resistances of both treated samples were highly improved after LSP, and a higher pulse energy corresponded to a more obvious effect. Besides, the wear in all test samples involved a combination of abrasive and oxidation wear and fatigue spalling.
关键词： laser shock peening,wear mechanism,impact wear,impact kinetic energy,Ti?6Al?4V alloy
更新于2025-09-12 10:27:22
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Microstructure and properties of homogeneous Cu90Fe10 immiscible composites with nanotwins by laser powder deposition: Effect of spot size
摘要： To select the reasonable spot size during laser powder deposition (LPD), the homogeneous Cu90Fe10 immiscible composites were produced by LPD with different spot sizes (2 mm and 4 mm in diameter). The LPD-produced Cu90Fe10 immiscible composites deposited with different spot sizes display a similar microstructure composed of a-Fe/g-Fe and ε-Cu phases. A large amount of nanoscale Fe-rich particles is uniformly embedded within the Cu-rich matrix and the Cu-rich particles with nanotwins are distributed within the Fe-rich particles due to secondary liquid phase separation (SLPS). Moreover, some nanoscale FeCr grains (~20 nm) are precipitated within the Fe-rich particles. Both the averaged diameter and grain size of Fe-rich particles reduce with decreasing the spot size due to higher cooling rate. The immiscible composite produced with spot size of 2 mm exhibits higher microhardness and elastic modulus (1.9 GPa and 143.5 GPa respectively) than the corresponding ones for the counterpart with spot size of 4 mm (1.8 GPa and 142.6 GPa respectively) and Brass. As a result, the LPD-produced Cu90Fe10 immiscible composite deposited with spot size of 2 mm exhibits higher wear and corrosion resistance compared to that deposited with spot size of 4 mm.
关键词： Nanotwins,Wear,Laser powder deposition,Corrosion,Particle-reinforcement
更新于2025-09-12 10:27:22
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A contribution to laser cladding of Ti-6Al-4V titanium alloy
摘要： A wear resistant coating was successfully made on an annealed Ti-6Al-4V titanium alloy by laser surface cladding using 60 wt.% WC + wt.% 40 NiCrBSi powder blends. Coaxial laser cladding was performed by means of Yb:YAG disk laser with a 3-KW continuous wave. Different laser interaction times were attempted to get the optimal conditions for promising mechanical properties. The new contribution was to accomplish larger clad layer thickness with applying the shortest possible laser interaction time that can achieve superior clad layer properties. This will decrease energy consumption with an expected money saving which is an essential factor for successful engineering solutions. A high powder ?ow rate of 20 g.min(cid:1)1 was intended in order to obtain a thick, nonporous and crack free clad layer. The clad samples were subjected to thorough microstructure investigations, in addition to microhardness and wear evaluation. The coating so produced exhibits multiple hardness values and exceptional wear resistance under adhesive/sliding wear conditions. The obtained results expose clad layer with superior quality that was achieved at a laser interaction time of 0.3 s. An enhancement in the microhardness values of the clad layers by more than fourfold was attained and the wear resistance was thus signi?cantly improved.
关键词： coaxial laser cladding process,titanium alloy,laser powder cladding,laser interaction time,microhardness,laser surface treatment,wear resistance
更新于2025-09-12 10:27:22
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Analysis of a Ni-Fe-Cr-Mo-Si hardfacing alloy manufactured by laser cladding: influence of the iron content on the wear resistance properties
摘要： In this article, we present an ongoing study on a Ni-Fe-Cr-Mo-Si based alloy, as one of the potential cobalt free hardfacing materials. Here, we analyze the effect of the variation of iron content on microstructure and wear property that is induced by a controlled dilution the 316L substrate, or by direct addition. First, we present the state of the art on the proposed Ni-Cr-Mo-Si based alloy. Then, the laser cladding setup is presented and the process parameter map search of the Ni-Fe-Cr-Mo-Si based alloy too. Then, iron is added to the base Ni-Cr-Mo-Si alloy by direct fusion of the powders coming from two different powder feeders and directly blended into the coaxial nozzle used. Finally the samples are analyzed in iron content, microhardness and microstructure. The tribology tests of the samples exhibit a clear change in wear behavior with the iron content and an improvement at a certain level of iron.
关键词： Tribology,Nickel Base Alloys,Laser Cladding,Hardfacing Materials,Nuclear Energy,Wear resistance
更新于2025-09-12 10:27:22
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Laser cladded Ti + TiB2 on Steel Rail Microstructural Effect
摘要： Rail transportation has been one of the most efficient and sustainable means of mobility with large economic value. The rail wheel flange steers on the rail track for motion with imparts of frictional force and rotational speed. High temperature is generated and prolific wear at high speed which is reduced by lubrication. Additive manufacturing techniques of laser cladding of steel rail surface were employed in this study with the ceramics of Titanium and Titanium boride powders at different mix ratio on steel rail surface. Different metallurgical characterization of cladded surface was carried out. The best hardness and microstructural view were noticed at 50:50 mix ratio of the cladded ceramics. The phase transformation of the varying mix ratio was also revealed.
关键词： Microstructure,Wheel flanges,Wear,Laser Cladding,Steel Rail
更新于2025-09-12 10:27:22