MEMS - filters

Gradient filter elements and membranes:

The conditions for layer-by-layer laser synthesis were studied either for homogenous and heterogeneous meso-devices made from metal and metal-polymer powder compositions such as porous filter elements, membranes. Parameters of the laser sintering (melting) process, aspects of computer design, content and composition of the “fine porous structure” were investigated. General methodological approaches of research on optimum conditions for SLS/M porous filter synthesis were improved and developed. Understanding the porous structure and its correlation to the performance of the porous materials is a scientifically and technologically important problem as this will permit a more appropriate design of these materials and extend the range of their applications. Advantages and drawbacks of such porous devices in MEMS-NEMS were discussed.

3D filter element. Material - Inox 316L . /ENISE ©/


Regular (square) type of cell shape.	Irregular (via CAD) type of cell shape.

It was offered the usage such porous samples as filter elements for hydro protection of submersed electric pumps. Primary goal of these filters is to execute separation of concomitant gases at oil extracting in aggressive environmental conditions (heightened temperature, pressure, tribomechanics and corrosive wear). After transit of laboratory seepage tests the filters have shown the unique characteristics on a number of parameters. Therefore synthesized by us via SLS method homogeneous filter were advised and successfully field tests have passed as filters of hydro-protection on several oil-fields. The temporary frameworks of the conducted tests with our filters essentially were bridged over as contrasted to by filters synthesized via powder metallurgy.

Appearance of filter elements for gas-oil industry /SB LPI ©/. Material - MPC. LI power Р = 10 W, laser scan velocity - 11,5 cm/s. From the left to right is property's changing by height:


Homogeneous filters: 1) MPC fraction size 63...100 mk, height increment from layer to layer h = 200 mk; 2) 100...160, h = 200 mk; 3) 63...100 , h = 100 mk; 4)<50 mk, h=200 mk.	Heterogeneous filters: 1) fraction size 63...100, height increment from layer to layer h = 200 mk , (it’s shown the 9 channels, as more light spots on the top surface); 2) 63...100 = const, height changed – h = 100, 150, 200, 250, 300, by 3 mm; 3) changing fraction size <50, 50...63, 63...100, 100...160 mk by 4 mm, h = 200 mk = const.

Fine porous structure optimization in frame work SLS/M approaches

Study of the influence of laser sintering /at Samara branch setup/ of LPI of RAS/ (melting /at PHENIX-100, ENISE, France/) regimes and powder materials on "fine structure" of filter /membrane/ and its working characteristic were conducted on following directions:

Accuracy and way reproduction of a single vector shifting on forming the each (first) layer;
Accuracy reproduction of angles of the part;
Accuracy reproduction wall of the part;
Accuracy of the laser syntheses of the filter with given a direction of the channel;
Possibility of the creation functional -graded filter elements.

SLS (SB LPI©), MPC, LI scan velocity V = 8,5 cm/s, beam diameter d = 300 mk.
SLM (ENISE©),Inox 316L

Accuracy reproduction of angles

Accuracy of the laser syntheses of the filter with given a direction of the channel

Accuracy reproduction wall of the part and a single vector

It was shown, that Functional Graded properties management of sintered filters is possible purposeful (i.e. before the experience) only in close interconnection with experimental dates by SLS in the narrow range of technological parameters of synthesis.