For a body, centre of volume is defined as  over complete body, where dV is small volume of body and r is position vector of that small volume from origin.

If density is uniform, then we can multiply $\rho$ in numerator ad denominator and take it inside integration sign.

$r_{volume}=\frac{\int \text{r}\cdot \text{dV}}{\int \text{dV}}=\frac{\int \text{r}\cdot \left(\rho \text{dV}\right)}{\int \left(\rho \text{dV}\right)}=\frac{\int \text{r}\cdot \text{dm}}{\int \left(\text{dm}\right)}=r_{mass}$

Thus, for a body of uniform density center of volume will be same as center of mass.