Regular elemental powders were used in warm flow compaction instead of the expensive micron-sized powders to fabricate cross-shaped parts. Debinding behaviors,sintering properties and shape consistency of the sintered parts were studied. Binder removal was accomplished by heating green compacts at intermediate temperatures with optimal heating rates until the debinding temperature was reached. Results show that by controlling debinding process,complex parts with good shape consistence can be obtained by warm compaction of binder-treated powder. Fine and shiny surface was obtained and no surface defect can be observed for sintered parts debinded at 2 ℃/min,while defect can be observed in sintered parts debinded at 4 ℃/min.
The sinter-hardening properties of a partially-diffuse alloyed Fe-2Cu-2Ni-1Mo-1C material were investigated. Samples were formed by die wall lubricated warm compaction method,then,sintered in hydrogen atmosphere at 1 150 ℃ for 1 h and cooled at 4.6,2.9 and 1.5 ℃/s,respectively,from 900 ℃ down to 600 ℃. Effects of cooling rate on mechanical properties and microstructure of the material were discussed. The results show that when the cooling rate increases,the tensile strength of the material increases,while,the elongation shows opposite result. The sintered material has a tensile strength of 872 MPa and an apparent hardness of HB 257 at a cooling rate of 4.6 ℃/s. Slight shrinkage is observed. Heterogeneous microstructures containing martensite,bainite,pearlite and nickel-rich retained austenite are observed in the material. Higher martensite content can be obtained at higher cooling rate,while,at lower cooling rate,pearlite and retained austenite dominated the microstructure.
