Influence of Laser Heating on the Properties of Coated Cutting Inserts

AbstractLaser heating of gold nanospheres (GNS) is increasingly prevalent in biomedical applications due to tunable optical properties that determine heating efficiency. Although many geometric parameters (i.e. size, morphology) can affect optical properties of individual GNS and their heating, no specific studies of how GNS aggregation affects heating have been carried out. We posit here that aggregation, which can occur within some biological systems, will significantly impact the optical and therefore heating properties of GNS. To address this, we employed discrete dipole approximation (DDA) simulations, Ultraviolet–Visible spectroscopy (UV–Vis) and laser calorimetry on GNS primary particles with diameters (5, 16, 30 nm) and their aggregates that contain 2 to 30 GNS particles. DDA shows that aggregation can reduce the extinction cross-section on a per particle basis by 17–28%. Experimental measurement by UV–Vis and laser calorimetry on aggregates also show up to a 25% reduction in extinction coefficient and significantly lower heating (~ 10%) compared to dispersed GNS. In addition, comparison of select aggregates shows even larger extinction cross section drops in sparse vs. dense aggregates. This work shows that GNS aggregation can change optical properties and reduce heating and provides a new framework for exploring this effect during laser heating of nanomaterial solutions.

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Improvement of thread turning process using micro-hole textured solid-lubricant embedded tools

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/09544054211019929 ◽

2021 ◽

pp. 095440542110199

Author(s):

Salman Khani ◽

Seyedhamidreza Shahabi Haghighi ◽

Mohammad Reza Razfar ◽

Masoud Farahnakian

Keyword(s):

Surface Roughness ◽

Mechanical Strength ◽

Solid Lubricant ◽

Operating Cost ◽

Contact Length ◽

Solid Lubrication ◽

Turning Process ◽

Micro Holes ◽

Micro Hole ◽

Cutting Inserts

In this paper, the thread turning of aluminum 7075-T6 alloy is studied using micro-hole textured solid-lubricant embedded carbide inserts. The primary focus of this work is to enhance the performance of the thread turning process for producing high quality threaded parts. To achieve this, micro-holes were generated by laser micro-machining on the rake face of tools and then, MoS2 and CNT (carbon nanotube) solid-lubricants were embedded into micro-holes. The effects of micro-holes and solid-lubrication on the performance of the thread turning process were examined using traditional tool ( T0), micro-hole textured tool ( T1), micro-hole textured MoS2 embedded tool ( T2), and micro-hole textured CNT embedded tool ( T3). In this study, cutting forces, chip-tool contact length, built-up edge (BUE), surface roughness, and operating cost were investigated. The influence of micro-hole generation on the mechanical strength of cutting inserts was evaluated using the finite element method. The results showed that the fabrication of the micro-holes on the rake surface of cutting inserts has no significant effect on the mechanical strength of the tools. The comparisons of our method with traditional tools demonstrated that the cutting performance improved in the threading process. Our results reveal that the main cutting force, radial thrust force, surface roughness, built-up edge, and chip-tool contact length reduced 37.1%, 40.9%, 37.9%, 58.3%, and 38.2%, respectively, as T3 tools are applied in this process. A cost analysis, based on estimated tooling costs, showed that the T3 tool can yield an 18% reduction in overall operating cost.

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Surface Conduction Effect of Laser Heating in Liquid Crystal Films

Journal of Optics ◽

10.1007/bf03549720 ◽

1997 ◽

Vol 26 (1) ◽

pp. 41-45

Author(s):

Mao Ye ◽

Jing-Guo Yang

Keyword(s):

Liquid Crystal ◽

Laser Heating ◽

Liquid Crystal Films ◽

Crystal Films ◽

Surface Conduction

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Feasibility of Cobalt-Free Nanostructured WC Cutting Inserts for Machining of a TiC/Fe Composite

Materials ◽

10.3390/ma14123432 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3432

Author(s):

Edwin Gevorkyan ◽

Mirosław Rucki ◽

Tadeusz Sałaciński ◽

Zbigniew Siemiątkowski ◽

Volodymyr Nerubatskyi ◽

...

Keyword(s):

Cubic Boron Nitride ◽

Cutting Tools ◽

Cutting Speed ◽

Machined Surface ◽

Powder Consolidation ◽

Plasma Sintering ◽

Cutting Inserts ◽

Spark Plasma ◽

And Performance ◽

Nanostructured Tungsten Carbide

The paper presents results of investigations on the binderless nanostructured tungsten carbide (WC) cutting tools fabrication and performance. The scientific novelty includes the description of some regularities of the powder consolidation under electric current and the subsequent possibility to utilize them for practical use in the fabrication of cutting tools. The sintering process of WC nanopowder was performed with the electroconsolidation method, which is a modification of spark plasma sintering (SPS). Its advantages include low temperatures and short sintering time which allows retaining nanosize grains of ca. 70 nm, close to the original particle size of the starting powder. In respect to the application of the cutting tools, pure WC nanostructure resulted in a smaller cutting edge radius providing a higher quality of TiC/Fe machined surface. In the range of cutting speeds, vc = 15–40 m/min the durability of the inserts was 75% of that achieved by cubic boron nitride ones, and more than two times better than that of WC-Co cutting tools. In additional tests of machining 13CrMo4 material at an elevated cutting speed of vc = 100 m/min, binderless nWC inserts worked almost three times longer than WC-Co composites.

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