合金元素Ni对铸铁短纤维烧结特性的影响

Effect of Element Ni On Sintering Characterastics Of Short Cast Iron Fibre

Ni 作为铁元素扩散的载体,显著加快了铸铁短纤维烧结体的致密化。当镍含量高于4.5%时,显微组织中发现了奥氏体,在奥氏体与珠光体边界析出断网状渗碳体,在奥氏体晶内析出魏氏碳化物及游离石墨,引起致密化速率下降,断裂方式由延性断裂转化为脆性断裂。

Nickel,as the carrier through which Fe atoms diffuse,obviously enha- nces the densification of sintered compact of short cast iron fiber.When Ni con-tent is above 4.5%,there are some austenite in microstructure at room temperature,and uncontinuous cementite networks at interfaces betw- een austenite and pearlite was found,widmannstatten carbide precipitates emerged at the interface of austenite and pearlite and free graphite precipi- tates was-discovered in austenite,which leads to the decrease of densific- ation rate and the fracture morphology of sintered compact changes from ductile to brittle.