Surface Roughness Parameters Rz Research Articles

Analyze the effects of CNC machining parameters on the surface roughness (Rz) of Anatolian chestnut

The effect of processing parameters on the surface roughness parameter Rz (mean peak-to-valley height) in CNC machining of Anatolian chestnut (Castenia sativa Mill.) wood species used in the woodworking and furniture industry was investigated. The machining conditions were determined to obtain the lowest Rz value. The experi-ments were carried out at the speeds of 8000, 12000, and 16000 rpm and the feed rates of 1000, 1500, and 2000 mm/min with 3 and 4 machining layers by using two different cutters with a diameter of 8 mm. Rz measurements were made on the obtained surfaces using the needle scanning method according to TS EN ISO 21920-2 (2021). In the measurements perpendicular to the fibers, the lowest Rz values were obtained with cutter type 2 (the cutter of the three cutting edge straight end mill), at 16000 rpm speed, 1000/2000 mm/min feed rate, and four machining layers. In the measurements made parallel to the fibers, the lowest Rz values were obtained at the cutter type 2 (the cutter of the three cutting edge straight end mill), at the speed of 16000 rpm and the feed rate of 1000/2000 mm/min and 4th step-down. A smooth surface (lower Rz value) was obtained with fourth cuts (step down, cut layer) instead of third cuts.

Surface quality and dry sliding wear behavior of AZ61Mg alloy using Abbott firestone technique

Currently, magnesium alloys are widely utilized in diverse sectors due to their unique properties. However, the AZ61Mg alloy, a commonly used magnesium alloy, is known to have poor wear resistance, which limits its applications. To address this issue, researchers have investigated various surface treatment techniques, including the Abbott Firestone method, to improve the wear resistance of this alloy. This study employs response surface methodology (RSM) to examine the effects of pressure and velocity on wear behavior and Abbott Firestone zones of AZ61Mg alloy. Three pressure (0.01, 0.015, and 0.02 MPa) and velocity (0.57, 0.76, and 0.95 m/s) levels are used to conduct dry sliding wear tests at room temperature using a pin-on-disc method with an experimental design technique (EDT). Analysis of variance ANOVA is employed to identify the relationship between the input parameters (pressure and velocity) and the responses (wear rate, Surface Roughness Parameter Rz, and Abbott Firestone zones) of the AZ61Mg alloy. The optimized models for wear rate and Abbott Firestone zones yielded accurate estimations, which can enhance cost-effectiveness and efficiency. The findings indicate that pressure and velocity significantly affect the wear behavior of the AZ61Mg alloy.

Effect mechanism and equivalent model of surface roughness on fatigue behavior of nickel-based single crystal superalloy

The global objective of this study was to systematically research the rule and mechanism how surface roughness affects the fatigue property of nickel-based single crystal superalloy. Fatigue tests of specimen with various levels of surface roughness were conducted at 980 °C and measured surface topography models were used to perform FE analysis based on crystal plasticity theory and fatigue damage model considering the resolved shear stress and slip rate of slip systems. Eventually, an geometrical equivalent simplification model with surface roughness parameters Rz, Rsm and Ra as modeling parameters for predicting fatigue life more convenient is proposed. Results indicate that micro-defects caused by surface roughness generate stress, plastic strain and damage concentration under fatigue load, which generate fatigue crack initiation, and greater surface roughness produces more severe concentration. The error between simulation prediction life and test result is within 3 times error band.

Study of technological parameters of steel Domex when high speed machining by monolithic ceramic milling tool

Abstract Experiment includes the study and identification of monolithic ceramic mining tools by machining the Domex 700 steel that belongs to the group of tough metals with high tensile strength. During the process of machining, the substandard high cutting speeds were used. Identification of ceramic mining tools included the analysis of cutting edge wear and the construction of map of surface roughness parameter Rz dependence on the change of cutting conditions for a given range (machine and material).

Evaluation of the surface profile obtained by abrasive jet machining

The abrasive jet machining is a machining method based on the effects generated by the action of the abrasive particles sent to the workpiece surface to be machined by means of a high pressure gas jet. Essentially, the obtained surface could be considered as constituted by chaining microcraters resulted as a consequence of the abrasive particles action. Taking into consideration the possible influence exerted by some abrasive jet machining process input factors, an experimental research was developed. By mathematical processing of the experimental results, empirical mathematical models were determined to highlight the influence exerted by the average dimension of the abrasive particles, the distance between the nozzle and the flat surface of the test piece and the impact angle on the surface roughness parameter Rz. In order to evaluate the similarities between distinct zones of the machined surface profile, the value of the Pearson’s coefficient was also determined.

Wpływ parametrów technologicznych na chropowatość powierzchni po toczeniu oraz predykcja chropowatości z użyciem sztucznych sieci neuronowych

The purpose of this investigation was to determine whether and to what extent the technological parameters of turning (feed, cutting speed) affect selected surface roughness parameters of aluminum alloy EN-AW 7075 (AlZn5.5MgCu). The principal findings indicate a significant impact of feed and show on the surface roughness and simultaneously show that cutting speed has no effect on the value of surface roughness parameters under investigation. An artificial neural network was employed to evaluate the prediction of surface roughness parameter Rz in turning.

Endermologie New Aproach in the Medicine Treatment

Abstract Experiment includes the study and identification of monolithic ceramic mining tools by machining the Domex 700 steel that belongs to the group of tough metals with high tensile strength. During the process of machining, the substandard high cutting speeds were used. Identification of ceramic mining tools included the analysis of cutting edge wear and the construction of map of surface roughness parameter Rz dependence on the change of cutting conditions for a given range (machine and material).

Prediction of surface topography in precision hard machining based on modelling of the generation mechanisms resulting from a variable feed rate

The paper presents an original contribution to the prediction of surface topography produced by precision hard turning operations using CBN cutting tools and the variable feed rate of 0.025–0.075 mm/rev. The differences between theoretical and real surface roughness parameters Rz and Sz are quantified in terms of springback effect, additional smoothing of irregularities and side flow effect. The primary experimental study includes measurements of 2D and 3D surface roughness parameters using contact profilometer. Correspondingly, cutting forces were measured using a piezoelectric dynamometer, and based on this data, specific corresponding values of ploughing energy and friction coefficient were determined. It was found that the measured value of maximum height of the surface Sz differs from the theoretical value mainly due to elastic recovery of the machined surface and the smoothing effect at the lower feeds and the elastic recovery and the side flow effect at the higher feeds employed. An empirical model for the prediction of the Sz value in function of the feed rate is derived. The prediction accuracy can be improved by advanced numerical modelling of surface generation mechanisms and associated distortions.

Considerations Regarding Some Surface State Parameters Characterized by a more Restricted Use

Frequently, on the drawings of mechanical parts, only indications concerning the surface roughness parameter Ra and, relatively rarely, the surface roughness parameter Rz are included. However, the study of the machined surface roughness highlights the necessity to use yet other surface roughness parameters, in order to have a clearer image on the state of the machined surface. Some other surface roughness parameters possible to be used and presenting importance, without the parameters Ra and Rz, were highlighted. One took into consideration the possibility of measuring parameters Rsk and Rmr by means of the available surface roughness testers. Experimental researches of turning by applying the method of full factorial experiment were developed. As input factors in turning process, the cutting speed, the feed rate and the tool nose radius were used. The experimental results were mathematically processed, being determined empirical mathematical models that highlight the influence of certain input factors of turning process on the values of some surface roughness parameters characterized by a more restricted use

Machinability investigations on turning of Cr-Ni-based stainless steel cladding formed by laser cladding process

Laser cladding process has been developed to be an advanced surface modification technique in re-manufacturing and maintenance fields. Service performance of the component formed by laser cladding largely depends on its subsequent finish cutting processes. Depth of cut in cladding turning process was restricted relatively small due to the thickness limitation of cladding layer, which reflected distinctive and crucial compared with cutting operations of homogeneous materials. The effect of depth of cut on turning performance of Cr-Ni-based stainless steel formed by laser cladding was investigated in this paper to get a novel insight into the machining process of cladding layer. Larger cutting force, worse surface roughness, and strengthened work-hardening with depth of cut increasing were observed similar to a conventional turning process. However, radial force rather than tangential force dominated especially in the given cutting conditions owing to the shallow depth of cut. Both surface roughness parameters Rz and Rt exhibited twice larger when the depth of cut exceeds 0.18 mm. Furthermore, comprehensive machinability of turning process was quantitatively evaluated based on modified digraph and matrix method so as to obtain a superior functional cladding. The results indicated that the machinability of cladding layer became worse with depth of cut increasing initially. The machinability value reached the worst level with depth of cut equaling to 0.24 mm. Thus, an optimized depth of cut was determined as 0.12 mm for turning of laser cladding Cr-Ni-based stainless steel. It should be noted that tool vibration should be eliminated for improved surface roughness as well as work-hardening with the depth of cut increasing, which performed beneficial to the machining of functional component formed by laser cladding.

Factors Analysis Affecting the Roughness at Side Milling

The study deals with evaluation of side milling factors, which influence the surface roughness parameter Rz. Four factors (diameter of milling cutter, spindle speed, feed per tooth and depth of cut) which enter into technological process of side milling of slots have been evaluated by means of full factorial analysis. The surface roughness has been evaluated by static quality characteristic from the peak to valley Rz parameter. The multiple linear regression equation ob- tained after analysis of variance gives the level quality Rz as a function of the significant factors. The main effect of dif- ferent factors and their interaction significance has been found, which generated surface profile under defined conditions by side milling.