An iron buckytube composite material was fabricated by direct melting. Rockwell hardness and microstructure of the composite material after quenching were investigated. Experimental results show that Rockwell hardness of the iron buckytube composite material can peak HRc65 after adaptable heat treatment and it is harder than common iron graphite alloy by 5~10HRc under the same condition. The analysis of microstructure indicates that there exists a kind of carbon rich white phase that emerged in marten...