Analysis of surface roughness and cutting force when turning AISI 1045 steel with grooved tools through Scott–Knott method

The chip breaker presents an important role in chip control on turning operation, as well as a significant influence on cutting force, surface integrity, wear, and tool life. In this experimental study, the grooved chip breaker, feed rate, and cutting velocity influence on cutting force and surface roughness of turning process of AISI 1045 steel were investigated through a complete factorial design and the Scott–Knott method. The multiple comparison method of Scott–Knott was used to identify which combination of the factor levels was specifically different when a source of variation was statistically significant in ANOVA. This multiple comparison method was essential to choose an optimal combination between cutting conditions and chip breaker type assuring the lowest cutting force and surface roughness levels without ambiguity. The methodology proposed was effective at achieving process improvement.     

Experimental studies of the cutting force and surface morphology of explosively clad Ti–steel plates

The present work pertains to the study of clad material such as titanium plated steel in drilling process. The study was conducted for two types of indexable insert drills with different configuration of the tool coatings (TiAlN/AlTiN + TiN and TiAlN/TiN), the same geometry of insert and fixed machining conditions. Drilling process was assessed by the analysis of thrust force, torque and signal fluctuations of PSD function. In this context, surface morphology of the drilled holes and contact area was analysed. It has been observed that the use of the PSD function allows assessment of the drilling process in different layers of clad materials. Also was found that the parameters of the surface morphology are dependent upon the type of layers of the clad and the type of drill. Furthermore the reduction in torque results in obtaining smaller values of surface roughness parameter especially in the area of volume parameters of the bearing area curve.     

Tribological properties of γ-Y2Si2O7 ceramic against AISI 52100 steel and Si3N4 ceramic counterparts

Reciprocating ball-on-flat dry sliding friction and wear experiments have been conducted on single-phase γ-Y₂Si₂O₇ ceramic flats in contact with AISI 52100 bearing steel and Si₃N₄ ceramic balls at 5–15 N normal loads in an ambient environment. The kinetic friction coefficients of γ-Y₂Si₂O₇ varied in the range over 0.53–0.63 against AISI 52100 steel and between 0.51–0.56 against Si₃N₄ ceramic. We found that wear occurred predominantly during the running-in period and it almost ceased at the steady friction stage. The wear rates of γ-Y₂Si₂O₇ were in the order of 10^?4 mm³/(N m). Besides, wear debris strongly influenced the friction and wear processes. The strong chemical affinity between γ-Y₂Si₂O₇ and AISI 52100 balls led to a thick transfer layer formed on both contact surfaces of the flat and counterpart ball, which changed the direct sliding between the ball and the flat into a shearing within the transfer layer. For the γ-Y₂Si₂O₇/Si₃N₄ pair, a thin silica hydrate lubricant tribofilm presented above the compressed debris entrapped in the worn track and contact ball surface. This transfer layer and the tribofilm separated the sliding couple from direct contact and contributed to the low friction coefficient and wear rate.     

Dynamic performance of a cable with an inspection robot — analysis, simulation, and experiments

A special cable inspection robot is designed to inspect automatically the cables of a cable-stayed bridge. The free vibration equation of the cable-robot system is derived firstly to study the dynamic characteristics and safety performance of the system. Then, the effect of the robot on the cable natural frequency is discussed, and the dynamic response equation when a robot is climbing at a constant speed is deduced. Furthermore, the effect of the cable vibration on the robot’s climbing ability is studied. The natural frequency characteristics of the robot are analyzed and optimized to avoid the resonance between the cable and the robot, using a finite element model. Additionally, dynamic cable responses are simulated under different conditions wherein the robot mass are 10 and 200 kg, and the speeds are 0.2 and 0.3 m/s, respectively. At last, to demonstrate further the dynamic characteristics of the cable-robot system experimentally, cables are set up on the Junshan highway bridge over the Yangtze river. Similar experimental models of these cables are constructed, and vibration experiments are conducted to validate the theoretical calculation. The results show that a light robot has little effects on the cable vibration amplitude and vibration acceleration; this confirms the safety of the cable.     

Effect on crystalline structure of AISI M2 steel using tungsten–thorium electrode through MRR,EWR, and surface finish

To investigate on the crystalline structure of AISI M2 steel by using tungsten–thorium electrode in electrical discharge machining (EDM) process was studied. Furthermore, the investigation were carried out for finding the value of material removal rate (MRR), electrode wear rate (EWR) and surface roughness (SR) of tool steel material depending upon three variable input process parameters. On the basis of weight loss, the value of MRR and EWR were calculated at optimized process parameter. Subsequently, surface topography of the processed material were examined through different characterization techniques like scanning electron microscopy (SEM), Optical surface profiler (OSP) and Atomic force microscopy (AFM), respectively. In XRD study, broadening of the peak was observed which confirmed the change in material properties due to the homogeneous dispersion of the particles inside the matrix. Lowest surface roughness and MRR of 0.001208 mg/min was obtained. Minimum surface roughness was obtained 1.12 μm and 2.18427 nm by OSP and AFM study, respectively. Also, minimum EWR was found as 0.013986 mg/min.     

Correlation between surface-hardness degradation and erosion resistance of carbon steel—Effects of slurry chemistry

The paper studied the effects of slurry chemistry on erosion of carbon steel. According to experimental measurements, the erosion rate in corroding slurries was a linear function of logarithm of anodic current density. In near-neutral or alkaline slurries, the erosion rates are independent of solution chemistry while the erosion rates in the acidic slurries were sensitive to slurry chemistry. To investigate the underlying mechanism, the in-situ surface hardness in corroding environments was measured with the nano-indentation technique under galvanostatic control. The results indicated that the surface hardness would decrease as anodic current was applied. The surface hardness degradation in near-neutral or alkaline electrolytes were almost unaffected by solution chemistry but that in acidic electrolyte depended heavily on solution chemistry. A linear correlation between the accelerated erosion and surface hardness degradation indicated that corrosion-induced surface-hardness degradation would be the dominant mechanism of corrosion-enhanced erosion.     

Investigation of cutting characteristics for worm machining on automatic lathe — Comparison of planetary milling and side milling

A worm and worm wheel gearing is widely used in a geared motor unit for the convenience and safety of an automobile. For mass production of a high quality worm, the current rolling process is substituted with the milling process. The milling process offers comparatively accurate machining quality and high production capacity for worm manufacturing. Moreover, since the milling process enables the integration of all operations of worm manufacturing on a CNC lathe, production efficiency can be remarkably improved. However, there are several important factors to be considered for producing high quality worms such as cutting force, tool-workpiece interference, and others. Planetary milling and side milling are generally applied to machine worms. In this study, the cutting characteristics of worm machining on an automatic lathe are investigated for two types of milling processes and those processes are compared with each other. A tool-tip trajectory model based on tool-workpiece interaction is proposed, and then tool-workpiece interference and cutting force are simulated with the model. The simulation results are verified through numerous experiments. The experimental results show the cutting characteristics of each milling process and the efficiency for mass production of a high quality worm. This paper was recommended for publication in revised form by Associate Editor Dae-Eun Kim     

Friction and wear of aluminium–steel contacts lubricated with ordered fluids-neutral and ionic liquid crystals as oil additives

Friction and wear of ASTM B211 aluminium–AISI 52100 steel contacts have been determined using pin-on-disk tests under variable conditions of normal applied load, sliding speed and temperature, in the presence of a lubricating base oil modified with a 1 wt.% proportion of three different liquid crystalline additives.The tribological behavior of the ionic liquid crystal n-dodecylammonium chloride (LC3) has been compared with that of two neutral liquid crystals: a non-polar species, 4,4′-dibutylazobenzene (LC1) which had previously shown its ability to lower friction and wear of metallic pairs as compared to the base oil, and a cholesterol derivative, cholesteryl linoleate (LC2).At low temperature and low sliding speed values, the friction coefficients obtained for LC1 are lower than those of LC3. As the severity of the contact conditions increases, this tendency reverses and the ionic species LC2 gives rise to lower friction values than LC1.Wear volume losses under increasing normal loads, between 2.45 and 5.89 N, are always lower in the presence of the ionic additive LC3.Lubrication and wear mechanisms are discussed from optical microscopy and SEM observation of the wear scars and wear debris morphology.     

Structure—phase transformations in contacting surface layers of coated steel during slipping friction with lubricant

Two approaches are used in simulating the thermal impact during the slipping friction of steel with lubricant, when high pressure is created and travels as an expansion—compression wave to the surface layers. This results in polymorphic transformation and anomalously fast diffusional mass transfer below the kinetic-transformation temperature. The pressure and diffusion coefficients are calculated.     

Deformation and strength properties of a carbon–carbide composite with 2D reinforcement under plane stress state

Data of an experimental–theoretical investigation of the deformation and strength characteristics of a carbon–carbide composite with a 2D reinforcement scheme are given. The nonlinear deformation of the material is described using the relationships of nonlinear elasticity of an orthotropic solid. The strength characteristics are calculated by the maximum stress criterion. Calculated deformation diagrams and ultimate strengths are compared with the experimental data of the authors.     

The effect of equal channel angular pressing on the mechanical and magnetic properties of 09Γ2C steel

The physical and mechanical properties of 09Γ2C steel that was subjected to strengthening by intense plastic deformation using the method of equal channel angular pressing (ECAP) are studied. An unambiguous interrelationship between the magnetic (coercive force, maximal permeability, Barkhausen magnetic noise parameters) and mechanical (rupture limit, conditional yield strength, relative elongation and narrowing upon damaging) characteristics of 09Γ2C steel, which was strengthened using ECAP following different technological regimes, is demonstrated. Therefore, it is possible to estimate the strength and plasticity characteristics of the analyzed material based on the measurement of its magnetic parameters. It has been revealed that under conditions of uniaxial tension in the range from 0 to (0.2–0.6) of the conditional yield strength (depending on the ECAP regime), it is possible to diagnose changes in the stressed state of items that are made of 09Γ2C steel that is hardened in accordance with the ECAP technique using magnetic structuroscopy methods.     

Magnetic properties and hardness of maraging steel 08X15H5Д2T and nondestructive testing of retained austenite in parts

Dependences of the coercive force, saturation magnetization, residual induction, relaxation magnetization and magnetic susceptibility, maximum magnetic permeability and associated magnetic field, electrical resistivity, and hardness of maraging steel 08X15H5Д2T on the conditions of preliminary heat treatments, hardening, and subsequent aging have been studied. The content of rtained austenite in specially prepared specimens was determined. These specimens were subsequently used to calibrate a differential magnetic instrument. Such an instrument is also used to determine the content of retained austenite in aircraft bolts.     

Ultra-fast 3D printing of assembly——free complex optics with sub-nanometer surface quality at mesoscale

Complex-shaped optical lenses are of great interest in the areas of laser processing, machine vision, and optical communications. Traditionally, the processing of complex optical lenses is usually achieved by precision machining combined with post-grinding or polishing, which is expensive, labor-intensive and difficult in the processing of ultra-complex optical lenses.Additive manufacturing is an emerging technology that provides significant advantages in producing highly intricate optical devic...     

Total and differential cross sections for proton-induced K-shell ionization — Comparisons of experimental measurements with recent data and with theory

A theoretical investigation of ion-induced K-shell ionization based upon perturbed-stationary-state theory is presented. Results of calculations using this theory are compared with new data for both total and differential cross sections. Total cross sections were measured for 0.3 to 2.4 MeV protons in Ti, Cr, Co, Ni, Cu and Zn. Differential cross sections were measured for 2 MeV protons in Cu and Ni and 3 MeV³He⁺⁺ in Cu. Comparisons of our data for the total cross section with recent data obtained by other groups and with other theoretical results are given. The overall agreement generally is to within 10% and frequently is closer.     

Development of a MIAB welding module and experimental analysis of rotational behavior of arc—simulation of electromagnetic force distribution during MIAB welding of steel pipes using finite element analysis

Magnetically impelled arc butt (MIAB) welding is a unique forge welding process in which an arc is drawn in the gap between the two tubes to be welded in order to raise them to a high temperature to allow forging to form a solid-state weld. In this case, the arc is rotated with a high speed around the weld line by an electromagnetic force resulting from the interaction of the magnetic field and the arc current. This paper presents the details of the results and the conclusions of the experimental trials conducted on the MIAB module designed and developed based on the principle. Further, nonlinear electromagnetic analysis has been performed to determine the magnetic field and electromagnetic force distribution in MIAB process using finite element package ANSYS. Typical results of this analysis pertaining to magnetic field are compared with the experimental data for steel tubes (outer diameter 47 mm and thickness of 2 mm). It is observed that the results from finite element analysis and the experimental trials are in excellent agreement. The proposed three-dimensional finite element method model for electromagnetic force distribution facilitates comprehensive understanding of the arc rotation process in MIAB welding.     

A knowledge-based approach for designing effective grooved chip breakers — 2D and 3D chip flow,chip curl and chip breaking

This paper presents details of a knowledge-based approach for designing effective grooved chip breakers for two- and three-dimensional chip flow, curl and breaking. The design criterion used in formulating this new approach is effective chip breaking at minimum power consumption. This work was aimed at achieving the optimum groove parameters and the best utilisation of groove profile under varying machining conditions. A systematic knowledge-pool was established from a series of well-designed machining experiments which form four knowledge databases (reference database, grooved chip breaker database, natural contact length database and 3D chip flow database). This paper shows how the chip breaker design parameters can be estimated for effective chip breaking at reduced power consumption. The basic tool design strategy presented in the paper also includes some guidelines, for cutting tool designers, highlighting the need for implementing a scientific approach for designing a chip breaker against the current practice of try and see methods.     

Optimisation of gain matrix with UZAWA algorithm—theory and application to an active panel

This paper deals with the gain matrix optimisation in the framework of adaptive mechanical systems with LQG control. The purpose of this optimisation is to provide to the engineer the theoretical tools enabling him to position actuators as well as possible on a structure. It was carried out using a conventional UZAWA algorithm which was adapted to the active system context.