CrSi2-based composites were fabricated by the WSi2 addition.
Grain size of CrSi2 phase was effectively reduced by the WSi2 addition.
The composite effects induced by the WSi2 addition effectively reduced κ of CrSi2.
The WSi2 addition had little effect on the thermoelectric power factor.
ZT value was enhanced and reached 0.3 around 700 K.