Finish Parameters Research Articles

Numerical analysis and experimental validation of conjunction gear via hot forging-upsetting finishing-radial extrusion

The formation of hot forging-upsetting finishing-radial extrusion (HF-UF-RE) compound into conjunction gears is an innovative process. This study describes the most existing manufacturing methods of the conjunction gear. Simulation and experimental research is conducted using this new method. First, a type of extrusion die is designed to form the back taper. The finite element models of hot forging, finishing, and radial extrusion are then established to estimate the feasibility of formation process of this compound. This study analyzes the law of metal flow in the process, the influence of the finishing parameters on the surface quality, and the distribution of stress and strain in extrusion. Metal flows from the tooth tip to the tooth bottom during the finishing process. The finishing qualities of different finishing parameters have been discussed. Local plastic deformation occurs at the tooth bottom during radial extrusion. The gears formed by each process are consistent with the designed shapes and meet the application requirements of the conjunction gear. HF-UF-RE is feasible for the formation process of conjunction gears.

Multi-objective optimization of ultrasonic-assisted magnetic abrasive finishing process

Ultrasonic-assisted magnetic abrasive finishing (UAMAF) is an advanced abrasive finishing process that finishes a workpiece surface effectually when compared to a traditional magnetic abrasive finishing process in the order of nanometer. A change of surface roughness and material removal rate are two important factors determining the efficacy of the process. These two factors affect the surface quality and production time and, thereby, a total production cost. The finishing performed at higher material removal rates leads to a loss in shape/form accuracy of the surface. At the same time, increasing the rate of change of surface roughness increases loss of material. For an optimized finishing process, a compromise has to be made between the change of surface roughness and the material removal (loss). In this work, a multi-objective optimization technique based on genetic algorithm is used to optimize the finishing parameters in the UAMAF processes. A fuzzy-set-based strategy for a higher level decision is also discussed. The results of the optimization based on a mathematical model of the process are validated with the experimental results and are found to be in compliance.

Laser assisted finishing process for improved surface finish of fused deposition modelled parts

Fused deposition modelling (FDM) is a popular Additive Manufacturing (AM) technology. AM based FDM process allows the fabrication of prototypes, tools and direct parts without any geometrical constraints. However, finishing issues such as visible rough patterns are inherent fabrication constraints of FDM parts, which limits the industrial scopes. The aim of this work is to provide the in-depth investigation of the finishing of fused deposition modelled polymer parts by the laser process. This research provided a novel strategy of coupling the FDM process and laser finishing. Empirical models have been developed for average surface roughness, skewness and kurtosis by which average and spatial properties (i.e., relative and combined) of profile distribution over the finished parts have been measured and analyzed. Practical parts have been dealt with in this paper and the change in roughness parameters have been analyzed before and after laser process. Empirical analysis has been used to understand main and interaction effects of different finishing parameters, namely the resolution and laser power, and the part build orientation during FDM. Empirical analysis presented that the interaction have more significant effects than main effects of laser power which is one of the individual parameters of the coupled operation. The experimental result of coupled operation shows that the developed laser assisted finishing process completely eliminates the visible rough patterns, thereby improving surface finish of FDM parts. This research also discussed importance of post finishing techniques and established the quantitative comparison between the published FDM finishing work and present technique to show the effectiveness of the proposed technique in relation to them.

Experimental research and modelling of life-cycle material removal in belt finishing for titanium alloy

The use of heat-resistant titanium alloys for the manufacture of gas turbine engine components for aerospace/energy applications, including the blisk, blade, casing, and bling, has become a routine exercise. Belt finishing is a good method for the precision manufacturing of titanium alloy components. However, normal belt finishing with elastic contact and grain wear might pose manufacturing challenges, especially when finishing processes are needed to control the cutting depth, remove the machining marks and establish a required workpiece surface quality and profile precision. Information on efficient finishing and material removal modelling of belt finishing for such sensitive industrial applications is scarce.This paper aims to establish a model of life-cycle material removal (LCMR) for a newly proposed method of BEF (belt efficient finishing) to realize the final precision finishing operation for components made of titanium alloy. Firstly, the theory model of LCMR is established by the curvature of LCMR for BEF based on the material removal mechanism of normal belt finishing. Secondly, the parametric mathematical models of LCMR for BEF of titanium alloy materials with flat and cylindrical surfaces are established by the method of least squares multiple linear regression analysis after orthogonal experimentation, and next, the F-test method is used to verify the significance of the model. Finally, the material removal of the BEF mechanism is analysed for different finishing parameters, conditions and movements with the single factor experiment method, and the parametric mathematical models of LCMR for BEF are simultaneously verified. Using this model, the life-cycle material removal can be predicted during belt efficient finishing of titanium alloy materials. The experimental and predicted results were in good agreement, and it could be concluded that the new method might be a viable process for finishing aero-engine components.

Analysis of Surface Texture of High Aspect Ratio Blind Micro Holes on Titanium Alloy (Ti-6Al-4V) in Micro Electrical Discharge Drilling

Efficiency of any machining process depends on the effectiveness of final outcomes. Surface integrity plays an important role in functional performance of a part or component. Traditionally, surface roughness is considered to be the principal parameter to assess the surface integrity of a machined surface. In this paper, the influences of machining parameters like gap voltage, capacitance and depth of hole on the surface finish parameters like Ra and Sa of micro holes have been studied in micro electrical discharge drilling. The high aspect ratio blind micro holes were drilled on titanium alloy (Ti-6Al-4V) with cylindrical tungsten tool electrodes. The experimentation was carried out adopting a full factorial design (33). The simultaneous effects of machining parameters on responses were analysed using response surface methodology. Multiple linear regression models were developed for responses to obtain the correlation between machining parameters and machining outputs. Multi-objective optimization has been performed with the aid of the desirability function approach.

Connection between surface microrelief of friction pairs and intensity of their attrition in non-stationary exploitation conditions

Comparing with the previous publications related to surface microrelief of friction pairs, this article focuses on investigation of workpiece surface interaction having different or similar, fully or partially regular slide surface microrelief and different or similar finish parameters. These parameters give an opportunity to spend minimum time for their bedding and further minimization of attrition intensitydependending on surface parts application, conditions of loading, lubrication etc.Further experimental investigations presuppose different friction pair materials, applied for guide equipment of different functionality with the aim of optional parameters and mating surface relief specification; also the ways for their processing in regard of meeting normative document requirements on hard and finish surfaces of machinery parts and mechanisms reported in related state standards.

Study on Type C Coal Fly ash as an Additive to Molding Sand for Steel Casting

Study of physio-chemical properties studies such as granulometric analysis, moisture, X ray fluorescence etc. were performed with Type C coal—combustion fly ash to investigate their potential as a distinct option for molding sand in foundry, thereby reducing the dependency on latter. Technological properties study such as compressive strength, tensile strength, permeability and compaction of various compositions of fly ash molding sand (10, 20 and 30 % fly ash substitute to chemically bonded sand) were performed and compared with silica molding sand. Steel casting production using this fly ash molding sand was done and the casting surface finish and typical casting parameters were assessed. It was noted that a good quality steel casting could be produced using type C fly ash molding sand, which effectively replaced 20 % of traditional molding sand and binders thereby providing greater financial profits to the foundry and an effective way of fly ash utilization (waste management).

Influence of nanofluid application on wheel wear, coefficient of friction and redeposition phenomenon in surface grinding of Ti-6Al-4V

Difficulties in the grinding of Ti-6Al-4V originate from the three basic properties: poor thermal conductivity, high chemical reactivity and low volume specific heat of the material. Under severe grinding conditions, all these factors together lead to the accelerated wheel loading and redeposition of chips over the work surface. Redeposition and wheel loading have a significant effect on the surface finish, grinding forces, power consumption and wheel life. In this study, water-based Al2O3 nanofluid as metalworking fluid is applied during the surface grinding of Ti-6Al-4V under minimum quantity lubrication mode after dressing the wheel with different dressing overlap ratios. The severity of the redeposition over the work surface was observed by measuring various surface profiles taken perpendicular to the grinding direction at several locations on the ground surface. The nanofluid application was able to prevent redeposition over work surface that became evident from the measured surface finish parameters that results along the grinding direction. Coefficient of friction was estimated On-Machine using the measured forces for different wheel work speed ratios, depth of cut and dressing overlap ratios. The results showed the effectiveness of nanofluid in reducing friction at high material removal rate (i.e. high depth of cut and high speed ratio) conditions when compared to the dry environment. From the measured forces variation with respect to the number of passes, it became evident that, nanofluid application delayed the frequency of wheel loading and grit fracturing cycle, which leads to the increase in the wheel life.

Grinding Behavior of Yttrium Partially Stabilized Zirconia Using Diamond Grinding Wheel

In recent development of dental restoration, zirconia has been used as a prosthetic material due to their enhanced properties of fracture strength and toughness compared to other ceramic materials. Zirconia based ceramic materials are used in structural application in engineering, such as in the manufacture of cutting tools, gas sensors, refractories. Grinding was used as the efficient technique to finish ceramic materials. Due to the hard and brittle nature of a ceramic material, the grounded components were left with surface and subsurface damages. In this paper, the influence of the grinding parameters on the grindability of yttrium partially stabilized zirconia was carried out using a diamond grinding wheel. The resin bonded grinding wheel was used to analyze the grinding behavior of the material. The grinding force and surface roughness were measured during the grinding process and the experiments were conducted under conventional flooded conditions. The relationship between the surface finish and grinding parameters such as depth of cut, wheel speed were analyzed.

Experimental investigation on part quality and metallic particle emission when milling 6061-T6 aluminium alloy

The quality of machining operations has a direct relationship with machined part quality and workshop air quality. The main characteristics that describe the machined part quality are burr size and surface finish, while fine particles are also considered as air quality characteristics in machining operations. In the present study, four main surface finish parameters (Ra, Rt, Rz and Rq), burrs size and mass concentration of metallic particles in milling of 6061-T6 aluminium alloy are investigated. The machining factors considered to build the experimental plan are cutting tool coating, insert nose radius, cutting speed and feed per tooth. The statistically significant responses to variation of process parameters and factors governing them are presented.

Grazing-incidence small-angle X-ray scattering in a twofold rough-interface medium: a new theoretical approach using the q-eigenwave formalism.

Based on the rigorous Green function formalism to describe the grazing-incidence small-angle X-ray scattering (GISAXS) problem, a system of two linked integral equations is derived with respect to amplitudes of the reflected and transmitted plane q-eigenwaves (eigenstate functions) propagating through two homogeneous media separated from each other by a rough surface interface. To build up the coupled solutions of these basic equations beyond the perturbation theory constraint 2kσθ0 < 1, a simple iteration procedure is proposed as opposed to the self-consistent wave approach [Chukhovskii (2011). Acta Cryst. A67, 200-209; Chukhovski (2012). Acta Cryst. A68, 505-512]. Using the first-order iteration, analytical expressions for the averaged specular and non-specular scattering intensity distributions have been obtained. These expressions are further analysed in terms of the GISAXS parameters {k, θ, θ0} and surface finish ones {σ, l, h}, where θ and θ0 are the scattering and incidence angles of the X-rays, respectively, σ is the root-mean-square roughness, l is the correlation length, h is the fractal surface model index, k = 2π/λ, and λ is the X-ray wavelength. A direct way to determine the surface finish parameters from the experimental specular and diffuse scattering indicatrix scan data is discussed for an example of GISAXS measurements from rough surfaces of α-quartz and CdTe samples.

Experimental investigation on wire vibration during fine wire electrical discharge machining process

Wire electrical discharge machining (WEDM) is extensively used in machining of conductive materials when producing precision products. Wire vibration has an important role in resulted cutting speed and surface finish. In this work, an investigation of the tungsten wire vibration during wire electrical discharge machining process with second cut conditions was performed. The vibration amplitude and frequency of wire were determined. Furthermore, the vibration mode of wire movements was investigated with changing the offset values. Also, the wire movement during WEDM can be recorded using a high-speed video camera. Cutting speed and surface finish values were measured. Then, the possibility of evaluating the wire vibration is also discussed and is related to the offset, cutting speed, and surface finish parameters. Also, the wire deflection, vibration power spectrum density, and amplitude envelope were also investigated.

Controlled grafting superhydrophobic cellulose surface with environmentally-friendly short fluoroalkyl chains by ATRP

Abstract Short fluoroalkyl chain of C3F7 instead of longer fluoroalkyl chain (C > 7) was robustly grafted on cotton fibers via an atom transfer radical polymerization (ATRP) strategy. This study focused on the influence of different finishing parameters (synthetic approach, grafting concentration) and post-treatment (washing, drying) conditions on wettability, liquid adhesion, air permeability, and mechanical (dry abrasion and wet laundering) properties. The results indicated that C3F7 chain was successfully grafting by a developed ATRP technique to construct superhydrophobic cotton fabrics. The optimized surfaces demonstrated super-anti-wetting property with a contact angle of about 163.7 ± 2.5° and an ultralow droplet adhesion of 62.3 ± 2.6 μN. The wettability remained highly hydrophobic even after 40 abrasion or 35 laundering cycles. This work also demonstrated the rational design and elaboration strategy of short fluorine-containing chains are vital for the construction of super-anti-wetting surfaces with controllable droplet adhesions. The results indicated that the anti-wetting, abrasion and laundering properties are much more influenced by the grafting strategy. We believe that environmental-friendly short fluoroalkyl chain (C

An Analytical Model of Residual Stress for Flank Milling of Ti-6Al-4V

Residual stress is one of the most critical parameters in surface integrity, which has a great impact on fatigue life of the machined components. While the flank milling of titanium alloy Ti-6Al-4V has been widely applied to the manufacture of jet engine for its high productivity in aerospace industry, prediction of residual stress induced by this process is seldom reported. In this paper, an analytical model of residual stress is proposed, based on comprehensive analysis of the mechanical loading during flank milling. For the first time, the sequential discontinuous variable loading feature of flank milling is taken into consideration. An incremental elasto-plastic method followed by a relaxation procedure is used to get the stress-strain history of an arbitrary point in the subsurface so as to predict the residual stress retained in the workpiece after several loading cycles. We find that during the last phase in which the machined surface is generated, the main load comes from the plough effect of cutting edge as the uncut depth approaches zero. The simulation results indicate that the flank milled surface shows more compressive residual stress in the axial direction than in the feed direction. To validate the prediction, a series of cutting tests are conducted on Ti-6Al-4V using finish parameters and X-ray diffraction is utilized to obtain the residual stress.

Fabric hand of a dry finished wool fabric

The appearance and hand of end-use fabrics has become more and more important when purchasing textile fabrics. The finishing parameters have complex influences on the large number of changes that occur in fabric properties during finishing processes. This study focused on the influences of different finishing parameters on mechanical and surface properties in order to discover the most appropriate finishing process according to the requirements of fabric handle and appearance. The KES-F system was used to evaluate fabric hand objectively, as well as the mechanical and surface properties of a woven wool fabric. Four finishing processes were selected, which differed in relation to the temperature when drying (T1=160 C, T2=180 C) and processing conditions during autoclave decatizing (T1=95 C, p1=0.4 bar, T2=110 C, p2=1 bar). The effect of the influential parameters inside four different finishing processes on the mechanical properties and hand of a selected woven fabric was evaluated using the analysis of variance. The results show that tensile properties are much more influenced by the belt pressing process while bending and shear properties are influenced by continuous decatizing process, which is the process that mostly improves fabric stability at the beginning of the dry finishing cycle. When the primary and total hand values were observed, it could be seen that applying chemicals during belt pressing had some consequences, the impacts of which could be observed directly in the resulting hand values.

Wine finish in red wine: The effect of ethanol and tannin concentration

Wine finish, the tastes and aromas that linger after swallowing wine, is a critical aspect of wine quality. The objective of this study was to use time-intensity (TI) methodology to determine whether the finish parameters of different flavors varied as a function of wine matrix composition. Trained panelists (n=10) executed TI evaluations on three flavor compounds (2-phenylethanol (floral), 3-isobutyl-2-methoxypyrazine (bell pepper), and oak lactone (coconut)), heat, and astringency in wine adjusted to varying ethanol and tannin levels. Multivariate analysis of variance indicated that elevated ethanol increased duration and intensity of the finish for floral and coconut samples (p<0.05). For floral and bell pepper, no significant differences were shown using canonical variates analysis (CVA); however, for coconut, the high ethanol samples were more associated with a higher finish intensity and longer duration of finish. Flavor interactions also affected finish duration, with coconut (oak lactone) finish duration shortened by 10.35s in the presence of 2-phenylethanol. These results showed that the wine matrix affects red wine finish and can be used by winemakers to understand how different processing techniques that alter the ethanol and tannin content of their wines, may also be affecting the sensory qualities of the wine finish.

Effect of Nitriding Cold Roled and Shot Peening on Automotive Component Fatigue Life

The finite element modeling and analysis have been performed to investigate the effects of nitriding, cold rolled and shot peening on fatigue life of an automotive lower suspension arm component which fabricated of SAE1045 steel. The finite element analysis (FEA) results indicate a great effect for all surface finish parameters on fatigue life. It shows that nitriding increased the fatigue life of the component better than shot peening, while cold rolled effect was between them. In a nut shell, nitriding can be considered as the best surface treatment to improve the fatigue life of the automotive lower suspension arm which fabricated of SAE1045 steel.

CNC Machining Based on UG for Stamping Die of Waveform Spring

In this paper, for the large scale production demand of waveform spring, it combines UG advantage of complex surface modeling and computer numerical control (CNC) machining, uses this way of surface modeling method of bicubic B-spline to establish the stamping die geometry model for the need of waveform spring production. And from a process point of view, it analyzes the key issues of die CNC machining to achieve the selection of optimal small tool radius, tool path rational planning and rough finishing parameters set. The application results show that: the shape precision of die surface could meet the design requirements and could achieve the precision stamping of waveform spring.

Investigation on surface finish and metallic particle emission during machining of aluminum alloys using response surface methodology and desirability functions

The surface finish of a mechanical part plays an important role as it determines the part’s field performance. The machining parameters and conditions governing the part surface finish also impact on the other machining process performance indicators such as tool wear, tool life, cycle time, machining cost, and undesirable emissions of aerosols and metallic particles. In today’s metal cutting industry, a major concern is the occupational safety and health hazard associated with cutting fluids usage and metallic particle emission. It is therefore necessary to determine machining conditions that could improve the part surface finish while maintaining low the aerosol emission. In this research study, statistical methods are used to study the surface finish parameters and the metallic particle emissions during milling of aluminum alloys (6061-T6, 7075-T6, and 2024-T351) with two coated carbide tools (TiCN and a multilayer TiCN + Al2O3 + TiN). Following an implementation of multilevel design of experiment, machining trials and determination of mains most influential factors, surface responses and desirability functions are used to determine the best process operational conditions and windows. The results of this research demonstrate that TiCN-coated tool generates fewer respirable airborne particles during machining than multilayers TiCN + Al2O3 + TiN-coated tool. Overall, it is shown that the use of TiCN coating tool provides a better opportunity for an environmentally benign dry machining along with improvement on surface quality.

Cutting temperatures when ball nose end milling γ-TiAl intermetallic alloys

Experimental results are presented for Ti–45Al–2Mn–2Nb+0.8vol% TiB2XD and Ti–45Al–8Nb–0.2C alloys. Three approaches were employed involving a constantan-workpiece thermocouple arrangement, implanted K-type thermocouples and IR thermography. New and worn (~300μm flank wear) coated carbide tools were used under dry conditions when down milling at 50–345m/min, with workpieces mounted horizontally and at 45°. Despite slight variation in ancillary finishing parameters there was generally good agreement between data sets for the different evaluation techniques employed and for both alloys. Higher temperatures were measured with the workpiece at 45°, with constantan-workpiece thermocouple temperatures of 375°C and 413°C for new and worn tools respectively at 345m/min.