Tool Life Research Articles

Assessing the Sustainability Impact of Improving Secondary Steel Production: Lessons Learned from an Italian Plant

Abstract This work presents a sustainability assessment approach to evaluate technological innovations in secondary steel production making use of Electric Arc Furnace (EAF) technology. The assessment covers the environmental, social, and economic dimensions of sustainability by combining different tools (Life Cycle Assessment and Analytic Hierarchy Process), and also provides an integrated assessment of the overall sustainability. The approach, which can also be used to support decision-making, has been applied to a real case study of a steel plant located in Northern Italy. In the case study, environmental sustainability is positively impacted mainly by increased metal yield and reduced furnace energy consumption. The greatest social sustainability benefits are mainly related to improved ergonomic and safety conditions for workers (reduced demand for physical effort, manual handling and repetitiveness, and lower risk of accidents), as a consequence of the introduction of Industry 4.0 technologies. Regarding economic sustainability, a positive impact related to reduced cycle time, increased metal yield and quality yield, reduced maintenance and quality control costs was observed. The integrated assessment of the overall sustainability has proven to be a viable approach to manage trade-offs between the different dimensions of sustainability.

Structure and properties of boride layers on low-carbon steel after plasma alloying with boron carbide

Wear is known to limit the life of tools and machines. To achieve high wear resistance, the hard phases must be individually adapted to the tribological system and especially to the interaction with abrasive objects. Comparison of the hardness of carbides, nitrides and borides of the same stoichiometry shows that borides usually have the highest hardness. Plasma doping with boron is an effective way to obtain boride layers with high wear resistance. In the work, a study of the microstructure, determination of the chemical composition in local places, measurement of microhardness and testing for adhesion to the substrate of the doped layer after processing were carried out. Based on the results of the research, it was found that the technology of plasma alloying with boron makes it possible to obtain a boride layer with high hardness and good adhesion to the substrate. According to the results of the study, the layer consists of several characteristic zones: hypereutectic, eutectic and heat-affected zones. The highest microhardness value of the alloyed layer is 1174 HV. It is noted that the hardening depth is 1.5 mm and is 5—6 times higher compared to the diffusion borated layer.

Application of Deep Cryogenic Treatment on Improving Service Life of Tools and Molds

Application of Deep Cryogenic Treatment on Improving Service Life of Tools and Molds

Optimization of Process Parameters for Machining of Steel Molds used for Aluminum Casting in Wheel Industry

The wheel industry, employing low-pressure casting techniques for producing lightweight alloy wheels, operates within a highly competitive manufacturing environment with significant production volumes. To fabricate essential mold core components for the aluminum wheel casting process, hot work tool steel alloys are selected for their exceptional durability and resistance to wear, fatigue, distortion, and high-temperature plastic deformation. Efficient machining operations for these steel molds require identifying optimal parameter combinations to minimize tool wear, surface roughness, and energy consumption while maximizing material removal rates. This study focuses on determining such parameters, utilizing DIN 1.2367 steel, to enhance manufacturing efficiency and meet industry requirements. The effects of machining parameters such as cutting speed, depth of cut, and number of inserts were investigated using the design of experiments. Depth of cut was determined as the most influential factor on tool wear, revealing the optimum parameter as 0.4 mm, followed by cutting speed. Notably, the number of inserts exhibits minimal direct impact but interacts significantly with the depth of cut, influencing wear patterns. This research contributes to sustainable machining practices by enhancing mold core manufacturing efficiency, prolonging tool life, and reducing tool wear. Such advancements are vital for the long-term competitiveness and environmental stewardship of the wheel industry.

Experimental Analysis on Turning of Super Duplex UNS 32750 Steel Using Minimum Quantity Lubrication Process

Current production trends necessitate extensive use of cutting fluids, resulting in adverse climatic changes and increasing industry expenses. Modern manufacturing businesses are looking for new ways to meet the demands for faster machining rates, less waste, and improved product quality while also lowering manufacturing costs. Material removal rate (MRR) and surface roughness (SR) of the work piece machined with coated tools are all evaluated. Cutting speed (CS), pressure flow (PF), and depth of cut(DOC), are the input parameters. An aerosol mixture of air and oil was used to give the least amount of lubrication. To assess the relative performance tuning with the MQL setup, an investigation was conducted. When compared to dry turning, the MQL system for turning super duplex stainless steel UNS 32750 has shown to be more effective. The MQL technique significantly improves cutting performance in terms of increasing tool life and improving machined component quality.

Effects of cutting conditions on the cutting forces in machining additively manufactured Ti6Al4V alloy

Machining of additive manufacturing (AM) process results in excessive consumption of the cutting power due to the high strength and hardness of the material produced that led to high cutting forces and short tool life during machining process. This paper aims to investigate the effect of cutting conditions and coefficient of friction on the cutting forces, during finite element analysis (FEA) of an orthogonal cutting of AM Ti6Al4V alloy bar. The FEA simulation considers three different experiments at low, medium, and high cutting conditions. The result shows that as the depth of cuts gets deeper and the cutting speed increases, the cutting forces were found to increase, leading to serrated or segmented chips formation. A cutting force of 1300.36N was observed at a cutting speed of 150 m/min and a coefficient of friction of 0.9. The cutting force was found to be weaker at the higher shear plane angle of 42.2o and higher at a smaller angle of 37.57o. The coefficient of friction was observed to be insignificant at lower value of 0.09 and was seemed to affect the cutting force at value around 1.

Predictive Modeling of Tool Life in Turning Using ANN‐Taguchi Hybridization

Predictive Modeling of Tool Life in Turning Using ANN‐Taguchi Hybridization

Quality Control Loop for Tool Wear Compensation in Milling Process using different Optimization Methods

Milling is one of the most important cutting processes in the manufacturing industry. Accordingly, optimization measures in this area have a great influence on the efficiency in modern production systems, which in many cases is composed of entire machine parks consisting of milling machines. Tool wear on milling machines reduces tool life and causes quality features of manufactured products to drift out of the target range. Currently, this is associated with a high effort to detect and control occurring deviations. In the following, an approach will be presented in which the design of an automated quality control loop for milling processes based on the geometric detection of the manufactured components is developed. The subject is formulated as a mathematical optimization problem, which is solved using evolutionary algorithms.

Economic analysis of eco-friendly lubrication strategies for the machining of Ti48Al2Cr2Nb aluminide

Titanium aluminides have been identified as potential materials in the aeronautical sector. However, the high processing costs and their low machinability limit their application. This research evaluates the effectiveness of minimum quantity lubrication technique (MQL) and cryogenic lubrication on the turning process of Ti48Al2Cr2Nb aluminide from an economic and industrial productivity point of view, with the aim of determining the optimum cutting conditions to reduce manufacturing costs and maximize the production rate. To this end, a preliminary experimental analysis will be carried out, determining the tool life as a function of the cutting speed for each lubrication condition (dry, MQL and LN2). The results show that, although both MQL and LN2 conditions allow the tool wear to be reduced, the MQL technique stands out for its higher efficiency and for the possibility of reaching a higher cutting speed. In addition, the high cost of liquid nitrogen implies a 47% additional cost. Consequently, this research finds out that the turning process should be carried out in the cutting speed range of 70–76 m/min under MQL conditions to obtain the highest profit rate.

Evaluation of tribo-vibration characteristics of the finishing turning process of heat-resistant structural steel 20MnMoNi5-5

This article is devoted to determining the rational range of cutting speeds during longitudinal finish turning of heat-resistant steel 20MnMoNi5-5 based on a set of tribological and vibration parameters of the cutting process. Turning workpieces with diameters D=120 mm made of 20MnMoNi5-5 steel with T15K6 carbide plates without cooling at finishing feeds and allowance values at cutting speeds of 100-220 m/min was carried out and studied. It was experimentally established that the local minimum for vibration energy was located within the speed range of 190-220 m/min. According to the results of tool life tests in this speed range, the wear rate of the cutting inserts was also minimized and the operating time of the tool was increased, making it possible to ensure the required surface roughness Ra≤1.6 μm.

双向犁耕防过载自动避障机构的设计与试验

During the tillage of two-way ploughing equipment in rocky and barren soil, due to hard objects such as stones, the plough and the key working parts such as plough column are deformed and broken, thereby reducing the reliability and service life of machines and tools. As such, an anti-overload automatic obstacle avoidance mechanism for two-way ploughing is developed. The maximum obstacle avoidance height is 40 cm, and the obstacle avoidance angle α is designed. The rotation range is 4.6 ~51.5°, and the effective compression stroke of the spring after pre-tightening is 39.34 mm. The motion equation and quasi-static force equation of the mechanism are established. The plowing resistance in the equilibrium state is 9.74 KN, and the required spring preload is 9.75 KN. Under the safety factor of 1.3, different spring elastic coefficients change with the rotation angle of the mechanism. The virtual prototype simulation model of the anti-overload automatic obstacle avoidance mechanism is established. The simulation results show that the mechanism can effectively perform the obstacle avoidance action. Bench test verifies that the mechanism can avoid obstacles according to the predetermined load. The field test shows that the stability coefficient of the ploughing depth of the mechanism is less than 8%. The results can effectively realize the obstacle avoidance function and ensure the farming quality, and provide an efficient and reliable anti-overload obstacle avoidance structure and parameter basis for the rocky land.

Wear mechanisms in Ti(C,N)-Al2O3 coated carbide during sustainable machining CGI

By replacing conventional gray cast iron (GI) with compacted graphite iron (CGI), automotive industry could keep up with stricter regulations on emissions and demands on higher engine performance. CGI has improved properties as to GI but is more difficult to machine. This study evaluates sustainable machining performance during finish face milling when using minimum quantity lubrication applied vegetable oil, resulting in 8% or 17–23% improved tool life respectively as to dry conditions. The main part of the study investigates the wear mechanisms in commercial Ti(C,N)-Al2O3 CVD-coated cemented carbide. The coating degrades by mechanically induced cracking and fractures, oxidation of adhered CGI inside cracks, diffusional dissolution of Ti(C,N) layer. Formation of softer (Mg,Fe,Mn)Al2O4 spinel is not observed but could be an expected reaction product. Other oxide inclusions, when deposited on cemented carbide surfaces, prevents adhesion of CGI material, and can reduce the wear rate where they are present. CGI adhering to cemented carbide induces diffusional loss of cobalt and carbon that eventually forms (Fex,Co1-x)3C iron carbide at the tool-workpiece interface which can reduce the diffusion rate. Novel findings also relates to the formation of 15 μm deep cracks in the cemented carbide due to inward diffusion of Fe accompanied by its oxidation that speeds up the oxygen ingress and further oxidation of W and Co. Oxidation was found to provide a positive effect when the adhered CGI completely oxidized to form Fe2SiO4 oxide ceramic Tool Protection Layer which slowed down tool material degradation.

A new grinding trajectory adaptive adjustment algorithm for circular-arc end mill flank based on grinding contact zone control

As one of the key structural features of the circular-arc end mill, the flank directly affects its service performance such as tool life and milling efficiency. Due to the curvature discontinuity of the flank edge curves and the inflexible posture of the grinding wheel, the existing grinding trajectory algorithms are difficult to accurately control the important end mill parameters such as the relief angle and flank width, and grinding interference is easy to occur. Therefore, this paper proposes a new grinding trajectory adaptive adjustment algorithm for circular-arc end mill flanks based on grinding contact zone control. Firstly, the edge curve equations are constructed through structural feature decomposition of the end mill, and the second flank is modeled based on uniform offset densification of edge curves. Then, the grinding wheel posture model is established and the contact zone between the grinding wheel and the first flank of the end mill is calculated. A grinding trajectory adaptive adjustment algorithm is then proposed, which iteratively modifies the lifting angle and swing angle of the grinding wheel and can avoid the abrupt change of grinding postures and the grinding interference, thus realizing accurate flank grinding. Finally, the corresponding algorithm module is developed on the VC++ platform, and the effectiveness of the proposed algorithm is verified by machining simulation and grinding experiments, therefore providing technical support for the accurate grinding of circular-arc end mills.

Penerapan Metoda High Pressure Jet Cooling (HPJC) untuk Mengurangi Keausan Tepi Pahat pada Proses Membubut dengan Kecepatan Rendah

High Pressure Jet Cooling (HPJC) is an alternative method to the ineffective and environmentally friendly flooding method for coolant distribution at the cutting contact area. This method is widely utilized in the machining process of materials that are difficult to cut or have superior mechanical properties using various tools that have high cutting speeds. At high cutting speeds, it will be difficult for coolant to penetrate the contact area. For this reason, in this study HPJC is used to turn low carbon steel material with a tool that has a low cutting speed. By using a tool capable of providing pressure variation in coolant delivery, flank wear as a result of the turning process was observed. The results were validated using ANOVA and Fisher Least Significant Differences methods. The results show that pressure variation can reduce the tool wear rate. However, the tools used were not sufficient to distinguish the change in applied pressure from the reduction in tool life. This is because the coolant is only concentrated on the main plane of the tool. As a result, other types of wear, namely nose wear, have increased.

Substrate surface processing in gas vacuum arc discharge

Problem. Preparation of the surface before the deposition of vacuum arc coatings is of great importance, as it affects not only the adhesive properties of the obtained coatings, but also the physical and mechanical properties of the substrate surface layer. The processes of ions interaction with the substrate surface during its ionic cleaning, before the deposition of coatings, have been relatively little studied and are almost not described in the literature. Goal. In this work, some of their features are considered in relation to the surface preparation of materials before the deposition of vacuum arc coatings. Methodology. The nature of the plasma interaction with the substrate material is determined by the ions energy and their flow density, other things being equal. The energy of the ions treating the substrate consists of their initial energy and the energy acquired in the Debye layer adjacent to the substrate when a negative potential is applied to it. The value of the potential at which the processes of condensation or sputtering are balanced is determined mainly by the nature of the vaporized material. When the value of the substrate potential increases, the deposited particles and its material are sputtered. At the same time, atoms on the substrate that are weakly connected to it, various impurities are removed, substrate temperature increases, especially in its surface layers. Results. The work investigates the influence of various metals and gases used to clean the surface of substrates made of cubic boron nitride PcBN and steels on the surface morphology. It was established that the use of gases (argon, nitrogen) for cleaning the surface of dielectric materials, in particular PcBN, showed the best results, which subsequently leads to an increase in the adhesion of the vacuum arc coating to the substrate. Practical value. The obtained results of investigation are of great practical importance. They can be used for the increasing of tool life and productivity of mechanical engineering.

Friction Comparison and Wear Analysis of Ceramic Cutting Tools Made from Alumina-Zirconia- Chromia Content

This research focused on wear analysis by using the coefficient of friction (COF) and high-speed CNC turning machine against ceramic cutting tools made from 80 wt.% Al2O3 - 20 wt.% ZrO2 mixed with 0.2 - 0.8 wt.% Cr2O3. The results showed that the sample with a composition ratio of 80 wt.% Al2O3 – 20 wt.% ZrO2 – 0.6 wt.% Cr2O3 demonstrated the lowest coefficient of friction of 0.305. In terms of tool wear, this cutting tool showed uniform abrasion marks on the flank wear, resulting in 60% - 80% better tool life compared to Al2O3 and Al2O3-ZrO2. Based on the observation by using SEM, analyses showed that grains were tightly bound to each other at a high cutting speed of 350 m/min and with a feed rate of 0.175 mm/rev, compared to Al2O3 and Al2O3- ZrO2 which showed visible chipping and notch. The addition of 0.6 wt.% Cr2O3 on Al2O3-ZrO2 composition was enough to increase the strength and reliability against ceramic cutting tools for machining purposes.

Influence of singular and dual MQL nozzles on sustainable milling of Al6061-T651 in different machining environments

Al6061-T651 alloy is widely used in the aerospace industry due to its superior properties and is a very difficult-to-cut material with high quality because of tool wear and thermal softening. This situation causes low surface quality, high cutting force, and limited tool life, as well as an increase in total consumed energy, total carbon dioxide emission, and total machining cost. Therefore, it is necessary to sustainably increase this aerospace alloy's machining performance. In the presented study, for the first time, milling performance and sustainability assessment of Al6061-T651 alloy under dry, minimum quantity lubrication (MQL), nano molybdenum disulfide (MoS2) reinforced nanofluid-assisted MQL (N-MQL) cutting conditions were investigated using the single nozzle and dual nozzles, two different MQL flow rates, and three different cutting speeds. In this context, the results of surface roughness, cutting force, feed force, cutting tool flank wear, total consumed energy, total carbon emission, and total machining cost were obtained. As the cutting speed increased, the cutting force, feed force, total consumed energy, total machining cost, and total carbon emission decreased by 12.9 %, 18 %, 7.8 %, 6 %, and 0.1 %, while the surface roughness increased by 34.9 %. In the MQL and MoS2 N-MQL cutting conditions at the same flow rate, using dual nozzles instead of a single nozzle improved machining response and sustainability indicators. In addition, increasing the flow rate improved machining performance and sustainability indicators. Using the double nozzle MoS2 N-MQL method reduced the surface roughness, cutting force, feed force, flank wear, total consumed energy, total carbon emission, and overall machining cost by 74.2 %, 63.9 %, 68.4 %, 66 %, 27.9 %, 0.4 %, and 6.39 %, respectively.

A comparative Life Cycle Assessment of vulnerable dwellings along Davao River Basin using Athena Impact Estimator for Buildings

Every year, more and more buildings are built, but many have problems because they are exposed to harsh weather and are used. Some of these problems are cracks, dead holes, and a high level of air infiltration, all affecting how much energy is used. This study aims to compare the embodied energy (EE) using life cycle analysis (LCA) of a row house model and a walk-up apartment model of housing in the riverine area of the Davao River. Assessment of the tool's life cycle is the research approach used for this investigation (LCA). A life cycle perspective can be helpful in several situations, including but not limited to better appreciating the potential benefits of the repurposing project and its impacts on the environment and providing information for future building stock management. Results have shown that row housing produces more building materials than walk-up buildings, with almost 50% less consumed. The row housing model also has a higher environmental impact on the assembly areas: foundation, roofing, and flooring materials. Meanwhile, walk-up dwellings contribute more wall components, columns, and beams. The findings of the life cycle assessments revealed that, in general, row housing units were impacted more during the production stage (A1 to A3), with 86% of the total. Throughout the same period, walk-up residences had a higher contribution during the construction phase (A4 and A5) with 11% and beyond the building life (D) with an average of 6%. Both models tie in with 2% for the use category (B2, B4, and B6) and 11% for the end-of-life category (C1 to C4). Row housing units impact the surrounding environment more than walk-up apartment units, assuming that the same measurement criteria are objectively applied to both models. According to the study's findings, implementing in-situ vertical development in sensitive areas is preferable because it involves less material consumption and has a smaller negative impact on the surrounding environment.

Investigating the supremacy of PVD S3p deposition over HiPIMS for AlTiN coating

Dry machining of Duplex Stainless Steel 2205 (DSS2205) is a challenging task due to difficulties including high cutting temperatures, work hardening tendency and Built-up Layer (BUL) formation. Moreover, the high demand for DSS stresses improving machining productivity and quality. This study focuses on inspecting the supremacy of the PVD Scalable Pulse Power Plasma (S3p) coating deposition technique, which is rarely used for dry machining DSS, over High Pulse Impulse Magnetron Sputtering (HiPIMS) to deposit AlTiN coatings. A combination of evaporation and sputtering used for S3p dominated over HiPIMS. After a machining length of 6240 mm, the AlTiN (HiPIMS) coatings were unable to sustain the dry machining conditions, exhibiting faster tool wear rates than the AlTiN (S3p) coatings. As a result, AlTiN (S3p) exhibited a tool life of 8840 mm, 1.6 times higher than the AlTiN (HiPIMS) coating. The effect of decreasing tool life at any selected cutting speed was more severe at higher feed rates (0.19 mm/rev). The tool life decreased by 56%, 32% and 23% for the uncoated, AlTiN (HiPIMS) and AlTiN (S3p) tools, respectively. The surface roughness and cutting force were found to decrease by a notable 13% and 10%, respectively, due to the excellent properties of AlTiN (S3p) coatings compared to AlTiN (HiPIMS) coatings.

Effect of noble gases ion implantation on the life time of WC-Co tools usedin wood-based material machining

Effect of noble gases ion implantation on the life time of WC-Co tools used in wood-based materialmachining. The results of the investigations on the tool life of WC-Co tools, implanted with three noble gas ions,i.e. helium, neon and argon, are presented in the comparison with the virgin tools and tools implanted withnitrogen ions. The surface modification of the tools was preceded by the modelling of the depth profiles of theimplanted elements. The implantation of the ions of noble gases resulted in an improvement in tool tool life, inthe range from 5 to 49%.