117 Polycrystalline finite element analysis of crystal orientation effect on surface roughness of pure titanium sheet

Lead-free piezoelectric (Bi1/2Na1/2)TiO3 (BNT) films were deposited on 1 mm thick pure titanium(Ti) substrates by a hydrothermal method. Tensile tests were performed to quantitatively assess the adhesion strength between BNT films and Ti substrates. Ti substrates were pretreated by chemical polish and mechanical polish respectively prior to BNT film deposition. In the tensile test, the behavior of BNT film exfoliation was investigated by the replica method. The critical Ti substrate strain inducing BNT film exfoliation was determined by the aid of finite element analysis (FEM). In this study, the results revealed that BNT film exfoliations were caused by the strain of Ti substrate, and the mechanical polish pretreatment improved the adhesion of BNT film to Ti substrate.

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Selective Laser Melting of PA 2200 for Hip Implant Applications: Finite Element Analysis, Process Optimization, and Morphological and Mechanical Characterization

Materials ◽

10.3390/ma14154240 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4240

Author(s):

Răzvan Păcurar ◽

Petru Berce ◽

Anna Petrilak ◽

Ovidiu Nemeş ◽

Cristina Ştefana Miron Borzan ◽

...

Keyword(s):

Finite Element Analysis ◽

Surface Roughness ◽

Finite Element ◽

Selective Laser Sintering ◽

Processing Parameters ◽

Laser Sintering ◽

Compression Tests ◽

Element Analysis ◽

Polyamide 12 ◽

Research Activities

Polyamide 12 (PA 22000) is a well-known material and one of the most biocompatible materials tested and used to manufacture customized medical implants by selective laser sintering technology. To optimize the implants, several research activities were considered, starting with the design and manufacture of test samples made of PA 2200 by selective laser sintering (SLS) technology, with different processing parameters and part orientations. The obtained samples were subjected to compression tests and later to SEM analyses of the fractured zones, in which we determined the microstructural properties of the analyzed samples. Finally, an evaluation of the surface roughness of the material and the possibility of improving the surface roughness of the realized parts using finite element analysis to determine the optimum contact pressure between the component made of PA 2200 by SLS and the component made of TiAl6V4 by SLM was performed.

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Nondimensional Analysis on the Mitigation of Hard Surface Roughness Induced Torque on Hard Cylinders by Introduction of a Soft Interfacial Layer for Precision Positioning Applications

Tribology ◽

10.1115/imece2006-15603 ◽

2006 ◽

Author(s):

Steven R. H. Barrett ◽

Alexander H. Slocum

Keyword(s):

Finite Element Analysis ◽

Surface Roughness ◽

Finite Element ◽

Interfacial Layer ◽

Maximum Torque ◽

Element Analysis ◽

Geometric Imperfections ◽

Positioning Accuracy ◽

Drive Roller ◽

Torque Values

It is widely known that surface roughness and other geometric imperfections can impose a limit on the positioning precision of actuators. The case of a hard cylinder rolling on a hard layer is investigated here, as it is applicable to friction drives. It is proposed that a soft interfacial layer between the drive roller and drive rail can mitigate the effects of geometric imperfections on positioning accuracy. Positioning accuracy is characterized by way of a 'roughness torque', which is the maximum torque that the roller sustains due to roughness of the rail. It is assumed that lower roughness torque values lead to greater positioning accuracy. Finite element analysis and an analytic approach are employed to investigate the situation.

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Performance study of a back-depression mechanical dry gas seal

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1243/1350650981542092 ◽

1998 ◽

Vol 212 (4) ◽

pp. 279-290 ◽

Cited By ~ 3

Author(s):

T. A. Stolarski ◽

Y Xue

Keyword(s):

Finite Element Analysis ◽

Surface Roughness ◽

Finite Element ◽

Roughness Parameter ◽

Design Procedure ◽

Control Parameters ◽

Roughness Parameters ◽

Performance Study ◽

Element Analysis ◽

Dry Gas Seal

An aerostatic mechanical dry gas seal is described in this paper. The seal has shallow depression grooves (compensators) on the back and annular grooves on one of the working faces. With the help of the back depression grooves, a hydrostatic pressure and thereby a separating force with satisfactory stiffness are produced within the sealing gap. A model which takes surface roughness into account was used to predict the performance of the seal. Relationships between the control parameters (the recess position, rG, the nominal film thickness, h0, the depth, hv, of depression grooves and the surface roughness parameter, a) are investigated against various pressure ratios, pe/ pi. The analysis provides a simple optimum design procedure. A finite element analysis was carried out to account for the effect of face deformation during operation of the seal. Experiments for various speeds, pressures and roughness parameters were carried out and the results from the experiments were used to validate the analysis performed. Analysis and experiment revealed the importance of the surface roughness and deformation of the faces for the creation and retention of the gap.

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