Fe-P-C-Cu-Mo系粉末合金的组织、性能及断口

研究了Fe-P-C-Cu-Mo系铁基粉末冶金材料中合金元素、烧结温度对合金组织及性能的影响,以及不同回火温度下磷的分布及其对合金断裂方式的影响。
通过研究得出:Fe-0.60%P-0-44%C-1.0%Cu-0.50%Mo合金在1160-1240℃烧结,保温1-2小时,可以获得较好的性能;若进一步经过850-900℃淬火,200℃或600℃回火,则合金的综合机械性能可以显著提高。通过试验发现:合金在200℃回火后,固溶在基体中的铝能抑制磷向晶界偏聚,使合垒断裂时呈现为穿晶断裂;400℃回火后,由于钼以碳化物形式析出,磷主要偏聚在晶界,造成合金沿晶断裂;600℃回火后,磷主要偏聚在孔隙表面,合金断口呈韧窝状。

STRUCTURES,PROPERTIES AND FRACTURES OF Fe-P-C-Cu-Mo SINTERED ALLOYS

This paper deals with the structures, properties and fracture modes of Fe-P-C-Cu-Mo sintered alloy. The effects of alloy elements and sintering temperature on structures and properties and the influences of phosphorus distribution on fracture modes at different tempering temperature have been studied.
Experimental results showed that good properties of Fe-0.60%P-0.44.%-1.0% Cu-0.50%Mo sintered alloy can be obtained after sintering at the temperature range of 1160-1240℃ for 1-2 hours.Its combined mechanical properties can be obviousiy improved after futher quenching from 850-900℃ and then tempering at 200℃ or 600℃. It was found in present experiments that when alloy was tempered at 200℃, molybdenum dissolved in matrix inhibited the grain boundary segregation of phosphous,and made the fracture modes of alloy become cleavage facture. Tempering at 400℃ causes intergranular fracture because during tempering at 400℃ molybdenum form molybdenum carbide, phosphorus mainly segregates into grain boundaries After tempering at 600℃, phosphorus segragates on the pore surfaces and fracture modes became ductile dimpled fractures.