Elastic properties of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi mathvariant="normal">W</mml:mi><mml:mrow><mml:mn>0.75</mml:mn></mml:mrow></mml:msub><mml:mi mathvariant="normal">R</mml:mi><mml:msub><mml:m

The high pressure equation of state for the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi mathvariant="normal">W</a:mi><a:mrow><a:mn>0.75</a:mn></a:mrow></a:msub><a:mi mathvariant="normal">R</a:mi><a:msub><a:mi mathvariant="normal">e</a:mi><a:mrow><a:mn>0.25</a:mn></a:mrow></a:msub></a:mrow></a:math> alloy is experimentally determined up to 183 GPa with synchrotron angle-dispersive powder x-ray diffraction in the diamond-anvil cell and to ∼925 GPa with density-functional theory. W-Re alloys are used in many industrial high-temperature applications and as a confining gasket material in high-pressure diamond-anvil cell research. The inclusion of 25 wt. % Re achieves the highest performance in terms of strength and ductility while also maintaining the body-centered-cubic (bcc) crystal structure, yet to date there has been no investigation into its elastic behavior at high pressure. We present the experimentally and theoretically determined volumetric and elastic pressure response and systematically compare these results to other W-Re alloys, finding that the bulk modulus of W-Re alloys varies nonlinearly with Re content and <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mrow><e:msub><e:mi mathvariant="normal">W</e:mi><e:mrow><e:mn>0.75</e:mn></e:mrow></e:msub><e:msub><e:mi>Re</e:mi><e:mrow><e:mn>0.25</e:mn></e:mrow></e:msub></e:mrow></e:math> becomes less incompressible than W at 85 GPa.