A triaxial linkage algorithm for the irregular surface machining of backplane using turn-milling compound method

2021 ◽  
Author(s):  
Yong Zhang ◽  
Yue Huang
Keyword(s):  
Irregular Surface ◽  
Surface Machining ◽  
Linkage Algorithm ◽  
Compound Method ◽  
Turn Milling

Synergistic effects of surface strengthening and surface micro-texture on aviation spherical plain bearing tribological properties

2017 ◽  
Vol 232 (7) ◽  
pp. 797-808 ◽  
Author(s):  
Zewei Yuan ◽  
Yue Qin ◽  
Chunli Deng ◽  
Peng Zheng
Keyword(s):  
Tribological Properties ◽  
High Speed ◽  
Synergistic Effects ◽  
Work Conditions ◽  
Rolling Process ◽  
Surface Material ◽  
Micro Hardness ◽  
Surface Machining ◽  
Surface Strengthening ◽  
Compound Method

With an increase in extreme and complex work conditions in the fields of aircraft industry and high-speed train, single surface strengthening or single surface machining is not satisfactory with repeated requests of spherical plain bearings, which results in serious wear. Therefore, in this paper, a compound method of ultrasonic surface rolling process and surface texture was proposed on the basis of investigating the wear mechanism to meet the tribological property requirements of spherical plain bearings. The theoretical and experimental results show that low micro-hardness and low shear strength of surface material, rough surface, and poor lubrication are the important factors contributing to the wear of spherical plain bearings. The surface roughness Ra and Rz of processed spherical plain bearings are reduced to 0.02 µm and 0.14 µm from 0.35 µm and 2.1 µm, respectively, and the micro-hardness of surface material is increased by about 20%. The double-sine micro-textures with the width of 120 µm and the depth of 20 µm produced by laser machine, together with the circular groove, provide satisfactory lubrication for the spherical plain bearings. Finally, the wear resistance properties of spherical plain bearings were increased by more than 55%. The proposed synergistic methods have great advantages in improving the tribological properties of key fundamental components, especially for spherical plain bearings.

LC–MS-MS Method for the Determination of Antidepressants and Benzodiazepines in Meconium

2020 ◽  
Vol 44 (6) ◽  
pp. 580-588
Author(s):  
A López-Rabuñal ◽  
E Lendoiro ◽  
M Concheiro ◽  
M López-Rivadulla ◽  
A Cruz ◽  
...  
Keyword(s):  
Extraction Efficiency ◽  
Solid Phase ◽  
Gradient Methods ◽  
Reversed Phase ◽  
Process Efficiency ◽  
Limit Of Quantification ◽  
Mode 2 ◽  
Positive Mode ◽  
Compound Method

Abstract An LC–MS-MS method for the determination of 14 benzodiazepines (BZDs) (alprazolam, α-hydroxyalprazolam, clonazepam, bromazepam, diazepam, nordiazepam, lorazepam, lormetazepam, oxazepam, flunitrazepam, 7-aminoflunitrazepam, triazolam, midazolam and zolpidem) and 15 antidepressants (ADs) (amitriptyline, nortriptyline, imipramine, desipramine, clomipramine, norclomipramine, fluoxetine, norfluoxetine, sertraline, norsertraline, paroxetine, venlafaxine, desmethylvenlafaxine, citalopram and desmethylcitalopram) in meconium was developed and validated. Meconium samples (0.25 ± 0.02 g) were homogenized in methanol and subjected to mixed-mode cation exchange solid-phase extraction. Chromatographic separation was performed in reversed phase, with a gradient of 0.1% formic acid in 2 mM ammonium formate and acetonitrile. Two different chromatographic gradient methods were employed, one for the separation of ADs and another for BZDs. Analytes were monitored by tandem mass spectrometry employing electrospray positive mode in MRM mode (2 transitions per compound). Method validation included: linearity [n = 5, limit of quantification (LOQ) to 400 ng/g], limits of detection (n = 6, 1–20 ng/g), LOQ (n = 9, 5–20 ng/g), selectivity (no endogenous or exogenous interferences), accuracy (n = 15, 90.6–111.5%), imprecision (n = 15, 0–14.6%), matrix effect (n = 10, −73 to 194.9%), extraction efficiency (n = 6, 35.9–91.2%), process efficiency (n = 6, 20.1–188.2%), stability 72 h in the autosampler (n = 3, −8.5 to 9%) and freeze/thaw stability (n = 3, −1.2 to −47%). The method was applied to four meconium specimens, which were analyzed with and without hydrolysis (enzymatic and alkaline). The authentic meconium samples tested positive for alprazolam, α-hydroxyalprazolam, clonazepam, diazepam, nordiazepam, fluoxetine, norfluoxetine, clomipramine and norclomipramine. Therefore, the present LC–MS-MS method allows a high throughput determination of the most common BZDs and ADs in meconium, which could be useful in clinical and forensic settings.

Optimization of turn-milling process in roughing and finishing regimes: Trade-off between productivity, cutting force and surface integrity

2021 ◽  
pp. 095440892199851
Author(s):  
Ebrahim Hosseini ◽  
Shafiqur Rehman ◽  
Ashkan Alimoradi
Keyword(s):  
Cutting Force ◽  
Desirability Function ◽  
Milling Process ◽  
Machining Process ◽  
Hybrid Machining ◽  
Trade Off ◽  
Hybrid Machining Process ◽  
Process Factors ◽  
Turn Milling ◽  
Selection Of

Turn-milling is a hybrid machining process which used benefits of interrupted cutting for proceeding of round bars. However, number of controllable parameters in the hybrid process is numerous that makes optimizing the process complicated. In the present study, an optimization work has been proposed to investigate the trade-off between production rate and cutting force in roughing regime as well surface roughness and tensile residual stress in finishing regime. Number of 43 experiments based on response surface methodology was designed and carried out to gather required data for development of quadratic empirical models. Then, the adequacy and importance of process factors were analyzed using analysis of variances. Finally, desirability function was used to optimize the process in rough and finish machining regimes. The obtained results showed that selection of eccentricity and cutter speed at their maximum working range can effectively enhance the quality characteristics in both the roughing and finishing regimes.

Research on Five-Axis Dual-NURBS Adaptive Interpolation Algorithm for Flank Milling

2010 ◽  
Vol 443 ◽  
pp. 330-335 ◽  
Author(s):  
Yu Han Wang ◽  
Jing Chun Feng ◽  
Sun Chao ◽  
Ming Chen
Keyword(s):  
Tool Path ◽  
Flank Milling ◽  
Interpolation Algorithm ◽  
Machining Time ◽  
Surface Machining ◽  
Tool Axis ◽  
Scanning Area ◽  
Nurbs Interpolation ◽  
Milling Method ◽  
Five Axis

In order to exploit the advantages of five-axis flank milling method for space free surface machining to the full, a definition of non-equidistant dual-NURBS tool path is presented first. On this basis, the constraint of velocity of points on the tool axis and the constraint of scanning area of the tool axis are deduced. Considering both of these constraints, an adaptive feed five-axis dual-NURBS interpolation algorithm is proposed. The simulation results show that the feedrate with the proposed algorithm satisfies both of the constraints and the machining time is reduced by 38.3% in comparison with the constant feed interpolator algorithm.

Development of CAM System for 3D Surface Machining With CNC Lathe (Tool Path Generation Considering Acceleration)

2014 ◽  
Author(s):  
Keigo Takasugi ◽  
Katsuhiro Nakagaki ◽  
Yoshitaka Morimoto ◽  
Yoshiyuki Kaneko
Keyword(s):  
Lead Time ◽  
Internal Combustion Engines ◽  
Tool Path ◽  
Tool Path Generation ◽  
Combustion Engines ◽  
Determination Method ◽  
Experimental Procedure ◽  
Surface Machining ◽  
Cnc Lathe ◽  
Lathe Tool

This study developed a method called non-axisymmetric curved surface turning (NACS-Turning) for a CNC lathe composed of a turning axis and two translation axes. The NACS-Turning method controls the three axes synchronously. This new machining method can reduce the lead time for non-circular shapes such as cam profiles or pistons for internal combustion engines. In our previous report, we presented an outline of a machining principle and a CAM system for NACS-Turning. However, at the same time, we found the problem that the X-axis slide exceeds the allowable acceleration. Therefore, it is preferable that the acceleration is verified during the cam application, and the tool path is generated within the allowable acceleration range. Therefore, this paper first describes the determination method of machinable conditions for NACS-Turning in the cam application. Next, based on the result, relationships between the acceleration of the X-axis slide and machining conditions are clarified. Finally, the experimental procedure showed that our proposed method does not exceed the allowable acceleration of the X-axis slide.

Curved surface machining through circular arc interpolation

1992 ◽  
Vol 19 (3) ◽  
pp. 329-337 ◽  
Author(s):  
G.W. Vickers ◽  
C. Bradley
Keyword(s):  
Curved Surface ◽  
Circular Arc ◽  
Surface Machining
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