Study on fatigue behavior of Fe-2Cu-2Ni-lMo-1C powder metallurgy material
In this paper,the bending fatigue behavior of a high density (7.30～7.40g/cm3) Fe-2Cu-2Ni-lMo-lC material,which was fabricated by die-wall lubricated warm compaction of partially-diffuse alloyed powder,was studied by ultrasonic fatigue testing.Influence of heat-treatment on the bending fatigue behavior of the sintered material was discussed.Results showed that the S-N curve of the sinter-hardened material decreased continually without the presence of the traditional horizontal plateau.Fatigue strength was 194,239,293 and 360 MPa at 108,107 ,106 and 105 cycles,respectively.After heat treatment,the S-N curve displayed the characteristic of multi-stage type,and two decreasing curves,which was separated by a horizontal plateau in the region of 105~107 cycles.The fatigue failure yet occured in the regime of exceeding 107 cycles.Fatigue strength was 205,293,419 and 549 MPa at 108,107,106 and 105cycles,respectively,after heat treatment.Fatigue strength after heat-treatment was higher than those in sinter-hardened state indicated that appropriate heat-treatment could improve the fatigue strength of P/M materials.Scanning electron microscopy revealed that cracks initiated from large pores or defects on the surface or near the sub-surface.Cracks propagated through trans-crystalline and inter-granular modes.Cleavage fracture and typical fatigue striations were observed in the crack propagation region of the sintered sample.Evidence of dimple ductile fracture was found in the rupture region of the samples.
Fe-2Cu-2Ni-1Mo-1C sintered material Heat treatment S-N curve Fatigue fracture
Zhiyu Xiao Ling Zhou Hong Wang Ngai Tungwai Leo Yuanyuan Li
School of Mechanical and Automotive Engineering,South China University of Technology,Guangzhou 51064 Department of Applied Mechanics and Engineering,Southwest Jiaotong University,Chengdou 610031
国际会议
成都
英文
269-274
2009-10-16（万方平台首次上网日期，不代表论文的发表时间）