 Bismuth is also used in Aluminum @-@ Silicon cast alloys in order to refine Si morphology . However , it indicated a poisoning effect on modification of strontium ( Sr ) . Some bismuth alloys , such as Bi35 @-@ Pb37 @-@ Sn25 , are combined with non @-@ sticking materials such as mica , glass and enamels because they easily wet them allowing to make joints to other parts . Addition of bismuth to caesium enhances the quantum yield of Cs cathodes . Sintering of bismuth and manganese powders at 300 ° C produces a permanent magnet and magnetostrictive material , which is used in ultrasonic generators and receivers working in the 10 – 100 kHz range and in magnetic memory devices . 
