#Yes, this is called metal foam.

See https://en.wikipedia.org/wiki/Metal_foam#Manufacturing_2

Foams are commonly made by injecting a gas or mixing a foaming agent into molten metal.[10] Melts can be foamed by creating gas bubbles in the material. Normally, bubbles in molten metal are highly buoyant in the high-density liquid and rise quickly to the surface. This rise can be slowed by increasing the viscosity of the molten metal by adding ceramic powders or alloying elements to form stabilizing particles in the melt, or by other means

And https://en.wikipedia.org/wiki/Metal_foam#Composites

Composite metal foam (CMF) is formed from hollow beads of one metal within a solid matrix of another, such as steel within aluminium, show 5 to 6 times greater strength to density ratio and more than 7 times greater energy absorption than previous metal foams.[15]

 

A less than one inch thick plate has enough resistance to turn a 7.62 x 63 mm standard-issue M2 armor piercing bullet to dust. The test plate outperformed a solid metal plate of similar thickness, while weighing far less. Other potential applications include nuclear waste (shielding X-rays, gamma rays and neutron radiation) transfer and thermal insulation for space vehicle atmospheric re-entry, with twice the resistance to fire and heat as the plain metals.[16]

Yes, this is called metal foam.

See https://en.wikipedia.org/wiki/Metal_foam#Manufacturing_2

Foams are commonly made by injecting a gas or mixing a foaming agent into molten metal.[10] Melts can be foamed by creating gas bubbles in the material. Normally, bubbles in molten metal are highly buoyant in the high-density liquid and rise quickly to the surface. This rise can be slowed by increasing the viscosity of the molten metal by adding ceramic powders or alloying elements to form stabilizing particles in the melt, or by other means

And https://en.wikipedia.org/wiki/Metal_foam#Composites

Composite metal foam (CMF) is formed from hollow beads of one metal within a solid matrix of another, such as steel within aluminium, show 5 to 6 times greater strength to density ratio and more than 7 times greater energy absorption than previous metal foams.[15]

A less than one inch thick plate has enough resistance to turn a 7.62 x 63 mm standard-issue M2 armor piercing bullet to dust. The test plate outperformed a solid metal plate of similar thickness, while weighing far less. Other potential applications include nuclear waste (shielding X-rays, gamma rays and neutron radiation) transfer and thermal insulation for space vehicle atmospheric re-entry, with twice the resistance to fire and heat as the plain metals.[16]

Yes, it is. This is called metal foam. See eg. https://en.wikipedia.org/wiki/Metal_foam :

Foams are commonly made by injecting a gas or mixing a foaming agent into molten metal.[10] Melts can be foamed by creating gas bubbles in the material. Normally, bubbles in molten metal are highly buoyant in the high-density liquid and rise quickly to the surface. This rise can be slowed by increasing the viscosity of the molten metal by adding ceramic powders or alloying elements to form stabilizing particles in the melt, or by other means

And

Composite metal foam (CMF) is formed from hollow beads of one metal within a solid matrix of another, such as steel within aluminium, show 5 to 6 times greater strength to density ratio and more than 7 times greater energy absorption than previous metal foams.[15]

A less than one inch thick plate has enough resistance to turn a 7.62 x 63 mm standard-issue M2 armor piercing bullet to dust. The test plate outperformed a solid metal plate of similar thickness, while weighing far less. Other potential applications include nuclear waste (shielding X-rays, gamma rays and neutron radiation) transfer and thermal insulation for space vehicle atmospheric re-entry, with twice the resistance to fire and heat as the plain metals.[16]

#Yes, this is called metal foam. 

See https://en.wikipedia.org/wiki/Metal_foam#Manufacturing_2

Foams are commonly made by injecting a gas or mixing a foaming agent into molten metal.[10] Melts can be foamed by creating gas bubbles in the material. Normally, bubbles in molten metal are highly buoyant in the high-density liquid and rise quickly to the surface. This rise can be slowed by increasing the viscosity of the molten metal by adding ceramic powders or alloying elements to form stabilizing particles in the melt, or by other means

And https://en.wikipedia.org/wiki/Metal_foam#Composites

Composite metal foam (CMF) is formed from hollow beads of one metal within a solid matrix of another, such as steel within aluminium, show 5 to 6 times greater strength to density ratio and more than 7 times greater energy absorption than previous metal foams.[15]

A less than one inch thick plate has enough resistance to turn a 7.62 x 63 mm standard-issue M2 armor piercing bullet to dust. The test plate outperformed a solid metal plate of similar thickness, while weighing far less. Other potential applications include nuclear waste (shielding X-rays, gamma rays and neutron radiation) transfer and thermal insulation for space vehicle atmospheric re-entry, with twice the resistance to fire and heat as the plain metals.[16]