Fabrication of TiZr-based bulk metallic glass foams with different gradient porosities for biomedical application

•TiZr BMGFs still remain amorphous state after fabrication by the hot pressing method.•Adjusting gradient porosities can manipulate the mechanical properties of TiZr BMGFs.•Cu spacer volume had no effect on TiZr BMGFs' glass-forming ability. Porous titanium zirconium (TiZr)-based bulk metallic glass foams (BMGFs) with different gradient porosities and Cu spacer particles were successfully fabricated through hot pressing. Two types of gradient porosity set as low-to-high (3 layers) and low-to-high-to-low (5 layers), with the porosities ranging from 0% to 50%, were used. The glass-forming ability of the samples of varying porosities did not differ, and the sample composed of the low-to-high-to-low gradient porosity type exhibited higher compressive strength and Young’s modulus across the range of porosities. Furthermore, the compressive strength and Young’s modulus of TiZr-based BMGFs can be controlled through a combination of gradient porosities.