Surface Modification Of Tools Research Articles

Tool skill impacts the archaeological evidence across technological primates

The archaeological record offers insights into our evolutionary past by revealing ancient behaviour through stone and fossil remains. Percussive foraging is suggested to be particularly relevant for the emergence of tool-use in our lineage, yet early hominin percussive behaviours remain largely understudied compared to flaked technology. Stone tool-use of extant primates allows the simultaneous investigation of their artefacts and the associated behaviours. This is important for understanding the development of tool surface modification, and crucial for interpreting damage patterns in the archaeological record. Here, we compare the behaviour and the resulting material record across stone tool-using primates. We investigate the relationship of nut-cracking technique and stone tool modification across chimpanzees, capuchins, and long-tailed macaques by conducting standardized field experiments with comparable raw materials. We show that different techniques likely emerged in response to diverse nut hardness, leading to variation in foraging success across species. Our experiments further demonstrate a correlation between techniques and the intensity of visible percussive damage on the tools. Tools used with more precision and efficiency as demonstrated by macaques, show fewer use wear traces. This suggests that some percussive techniques may be less readily identified in the archaeological record.

Life cycle comprehensive performance assessment of the TiAlN coated tool based on surface treatment

The optimal surface treatment process can availably improve tool surface properties, and meet the requirements of low-carbon manufacturing. In this work, based on tool surface modification technology and tool life cycle carbon emission system, TiAlN coated tools are carried out micro-blasting treatment (MBT), cryogenic treatment (CT) and heat treatment (HT). The effects of surface treatment processes on the surface integrity (morphology, roughness, micro-hardness, residual stress) of the coated tool are studied. The high-speed dry finishing turning experiments of cobalt-based superalloy are carried out to investigate the tool wear morphology and wear mechanism. The carbon emissions of the tool life cycle are analyzed. Finally, the comprehensive performance of the coated tool within life cycle is evaluated. The results show that the highest level of surface integrity of coated tool is achieved by MBT, while the lowest carbon emission of environmental is impacted by HT. Compared with the untreated (UT) tool, the micro-blasted tool has the most significant improvement in surface roughness with a 28.6% reduction. The cryogenic treated tool has the greatest improvement on the surface hardness which is increased by 44.4%. The effect of HT on the surface residual stress is the most obvious. The surface stress of the heat-treated tool has increased by 59.4%. Moreover, the flank wear VB of the micro-blasted tool, cryogenic treated tool and heat-treated tool is reduced by 25.17%, 24.50% and 32.12%, respectively. The main wear mechanisms of the treated tool are adhesive wear, oxidation wear and abrasive wear. According to comprehensive performance assessment, the performance of surface treatment process during the coated tool life cycle is: HT > MBT > CT > UT.

Tool surface modification methodology to improve the machinability of Ti6Al4V through combination of micro-EDM texturing and AlSi-10Mg soft coating techniques in dry turning

Machinability of Ti-6Al-4V, despite its numerous applications, is challenging owing to its poor thermal conductivity, severe chemical affinity and strain hardening characteristics. Although various coating techniques and expensive lubrication strategies have been tried, a significant improvement in tool life characteristics are yet to be achieved. Hence this work aims at suggesting a novel cost-effective and ecofriendly tool treatment technique by exploring the impact of a dual combination of an AlSi-10Mg coating developed by an emerging pre-conditioning technique with the incorporation of micro-textures on tool face to observe significant improvements in tool life and machinability characteristics of the alloy. It was analyzed from the results that while the micro-textures played a vital role in reducing the severe contact stress and machining temperature due to its improved heat transfer by convection, AlSi-10Mg film effectively shielded the cutting edges of the tool by providing a dampening effect along the edges, thereby ensuring improved tool life and enhanced machinability characteristics at the same time. The proposed tool combination was observed to be successful in significantly reducing the flank wear by 35%, 43% and 30% where 75, 253, and 371 µm were observed at 80, 100, and 120 m/min as compared to 117, 449, and 531 µm in the case of uncoated non-textured tool at the same operating conditions. Surface roughness of Ti-6Al-4V also reduced by 25%, 34%, and 37% where 1394, 1168, and 872 nm as compared to plain tool where 1840, 1770, and 1370 nm were recorded. Moreover, average chip curl diameter was observed to be 2.62, 3.36, and 6.49 mm as compared to chips generated by uncoated tools which recorded values of 4.33, 11.9, and 18.87 mm at 80, 100, and 120 m/min respectively.

Localized Laser Dispersing of Titanium-Based Particles for Improving the Tribological Performance of Hot Stamping Tools

Within the scope of this work, a new surface engineering technology named laser implantation has been investigated, in order to improve the tribological performance of hot stamping tools. This technique is based on manufacturing highly wear-resistant, separated, and elevated microfeatures by embedding hard ceramic particles into the tool surface via pulsed laser radiation. Hence, the topography and material properties of the tool are modified, which influences the thermal and tribological interactions at the blank-die interface. To verify these assumptions and to clarify the cause–effect relations, different titanium-based particles (TiB2, TiC, TiN) were laser-implanted and subsequently analyzed regarding to their geometrical shape and mechanical properties. Afterwards, quenching tests as well as tribological experiments were carried out by using titanium-diboride as the most promising implantation material for reducing the tribological load due to high hardness value of the generated implants. Compared to conventional tooling systems, the modified tool surfaces revealed a significantly higher wear resistance as well as reduced friction forces while offering the possibility to adjust the thermal interactions at the blank-die interface. Based on these results, a tailored tool surface modification can be pursued in future research work, in order to enhance the effectiveness of the hot stamping technology.

From macro to micro, evolution of surface structures on cutting tools: a review

In modern tool industry, the design and manufacture of cutting tool surface have been highlighted to fulfill the ever-increasing demands of advanced manufacturing, e.g., lean production, intelligent manufacturing and Industry 4.0. Chip-breaker is a triumph of applying the specific macro structure on rake face, not only contributing to chip controlling, but also being capable to reduce cutting force and tool temperature. In recent decade, surface texturing has been emerged on tool surface, indicating that research focus of surface structures on tools is evolving from macroscale to microscale. The present study reviews functions, optimization and manufacture approaches of different scale structures on cutting tools, aiming at providing a global view of related technologies and revealing the possible developing tendency in this field. This paper could greatly facilitate future research and industrial application of tool surface modification, especially for the integrated application in multi-scale.

Performance of laser processed carbide tools for machining of Ti6Al4V alloys: A combined study on experimental and finite element analysis

Tool surface modification strategies are expected to achieve energy efficient dry cutting pertaining tribological advantages of textured surfaces. Current work focuses on both experimental and finite element based approaches to understand the effect of textured and coated textured tools on machining performance of Ti6Al4V alloy. Novel chevron textured tools were fabricated using nanosecond fiber laser and further coated with PVD-TiAlN coating. 2D FE simulation studies for turning with uncoated textured and TiAlN coated-textured tools were performed and compared with plain and coated-plain tools. The effectiveness of the textured tools is evaluated in terms of cutting forces, average friction coefficient, tool-chip contact length, chip disentangling behavior, and shear stresses between coating-substrate adhesions. Results confirm that the coated textured tool is helpful in machining performance improvement of Ti6Al4V alloys even at comparatively higher cutting speeds and feed. The concept of interface multipoint micro-cutting (IMP-μC) at varying machining speeds was observed from FE simulations and verified from experimental results.

Probing the potential of structured and surface functionalized tools for dry cold forging of aluminium

In order to reduce friction and wear in cold forging of aluminium and its alloys a tremendous amount of lubricants is used. The main task of the liquid lubricants is the separation of tool and workpiece surfaces to avoid adhesion and abrasion. From an ecological and economical point of view, a reduction of the consumption of lubricants is meaningful. Novel surface modification techniques have been investigated to enable dry cold forming. In previous work, a reduced wear by adhesion of aluminium to an AISI H11 ESR tool steel surface was detected for a combination of laser polishing and a subsequent surface functionalization. Here, structured surfaces combined with surface functionalization are investigated regarding their wear behaviour. Therefore, different structures are realized on AISI H11 ESR tool steel surfaces by laser structuring. These structures are aligned parallel and perpendicular to the material flow direction. Furthermore, different structure depths are generated. It is evident that the laser induced surface melting causes both, a reduced micro roughness as well as a homogenized elementary distribution. Moreover, the surfaces are functionalized with an octadecylphosphonic acid selfassembled monolayer (C18PA-SAM). The SAM’s distal alkyl termini functionalize the tool steel surface und thus only weak van-der-Waals interactions are present in the aluminium-tool steel interface rendering an interaction, which is expected to be similar to the interaction in conventionally lubricated aluminium forming. Finally, the surfaces are appraised regarding their wear behaviour in a compression-torsion-wear tribometer. The different experimental results document the potential of the here investigated combined tool surface modification. Although, the performance of a lubricated process is not completely reached a reduction in friction and wear can be achieved compared to unmodified tools.

Surface Modification of Tools by Electrical Discharge Treatment in Electrolyte

Surface Modification of Tools by Electrical Discharge Treatment in Electrolyte

Fabrication and Characterisation of Nanostructured Coatings by Magnetron Sputtering for Wear Resistant Applications

Magnetron sputtering is a powerful process for the production of thin films and coatings employed for the surface modification of tools and engineering components in various industrial sectors. Nanostructured coatings for multifunctional applications were deposited by means of magnetron sputtering by adjusting the experimental parameters in order to tailor the chemistry, the microstructure and the morphology of the coatings. Among the several systems that were investigated, TiC–TiB2 for wear applications were successfully tested. TiC–TiB2 coatings were deposited on a hardmetal WC–Co substrate in an unbalanced DC magnetron sputtering system starting from composite targets fabricated by the Self-propagating High-temperature Synthesis (SHS) consolidation method, involving the material synthesis and densification in one step. The results, showing the achievement of nanostructured films with thickness ranging between 1 and 2 µm, are here presented. The properties evaluated on the developed films (hardness, adhesion, friction coefficient and volumetric wear) are promising for the improvement of wear-resistant applications.

Study on properties and microstructure of Ti–Si–N coatings deposited in deep holes

Nanocomposite coatings have a great superiority of industrial application in surface modification of tools and dies due to special properties such as compatible microstructure, excellent mechanical properties and favorable chemical stability. In this study, Ti–Si–N coatings were deposited on polished high speed steel (HSS) W18Cr4V by industrial-scale pulsed d.c PECVD plant. The structure of Ti–Si–N coatings deposited at the bottoms of deep holes with different height was investigated by X-ray diffraction and X-ray photoelectron spectroscopy. With the increase of the measured depths at the bottom of the holes, the silicon content in the Ti–Si–N coatings increases, while nanocomposites made of crystallite phase TiN, TiSi 2 and amorphous Si 3N 4 was found in deeper hole. Thickness and bonding strength of coatings increases with the increase of pulsed frequency, which may result from the change of the cathode-sheath thickness ( S). It was found that S and hardness of the coatings have a dependence on φ / h 2, where φ and h are diameter and height of the deep hole, respectively.