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SISAlloy® (Yttria/Rhenium Alloy) MS Filaments

Mass Spectrometer Filaments that reduce or eliminate filament sagging


SIS introduces their new Yttria Rhenium alloy filaments for mass spectrometers. These filaments resulted from an intensive three year study and investigation at SIS on mass spectrometer filament life and performance. In these studies we have discovered that by alloying Rhenium with a small concentration of Yttria, the crystal structure of the rhenium material was altered, which resulted in a stronger filament that is much less susceptible to warping. The new filaments perform electrically identical to pure rhenium filaments.

The two examples below demonstrate the comparison of pure Rhenium to the new SISAlloy® (Y/Re alloy) filaments. By reducing warping and sagging the life of the filaments is improved.

Electron microscopy studies demonstrated that the yttria oxide particles intermixed with the rhenium particles which minimized the grain growth in the alloy filament. In comparison, the pure rhenium filaments exhibited larger and longer grain sizes. This smaller grain size in the alloy filament appears to strengthen the filament wire to provide a more stable filament that displays less sag or warping than pure rhenium filaments. The property of holding its shape has been demonstrated for straight wire filaments, multiple coiled filaments and pin shaped filaments when used in both AC and DC filament operating circuits.

SISAlloy Filaments from SIS

The New SISAlloy filaments are now available for SIS customers. Your existing filaments can be repaired with this Yttria/Rhenium wire in place of the standard Rhenium. SISAlloy repaired filaments are available for most models of the Agilent, Varian and Thermo Mass Spectrometers. Other filaments will be available in the near future.

* SISAlloy® is a trademark of Scientific Instrument Services, Inc., patent US 2010/0277051 A1.


Ordering Information

For ordering, see MS Filament Repair.

Related Products
  • SISAlloy® filaments with Yttria coatingSISAlloy® filaments with Yttria coating
    SIS can repair your filaments with our non-sagging filament wire (SISAlloy® yttria/rhenium alloy with yttria coating). Users have experienced filament lifetime increases of 2 to 3 times compared to the standard uncoated rhenium filaments.