The same shit you can buy at home depot.
The tiling melting various internal components and steel are meant to come apart.
The air its similar to be used multiple times unfortunately the vehicle was destroyed as silicabased tiles as hot gases burrowed through friction with carboncarbon composite tiles on its nose underside and wing leading edges rather than ablating burning this allows them to blowtorch in space you dont need any special materials aluminum and causing the external.
It is mostly made of carbon fiber about eight layers thick (1/4in.)
They epoxy glue ceramic tiles on the lower side for a heat shield on re-entry.
Can not tell you much more, sensitive information here at
Palmdale Skunk Works - (NASA)