【摘要】 研究了钨含量为36%,Ni与Fe质量比为7/3和9/1的两种W Ni Fe三元合金的预应变时效硬度变化规律,用X射线衍射鉴定了时效后两种合金的物相组成,并用透射电镜观察其微观结构。结果表明:Ni与Fe质量比为7/3的W Ni Fe三元合金在800℃下进行预应变时效时,硬度随时间增加而单调降低;相同条件下Ni与Fe质量比为9/1的W Ni Fe三元合金时效初期硬度下降,但随时间延长硬度又逐步提高。X射线衍射物相鉴定和透射电子显微分析发现:Ni与Fe质量比为7/3的合金在预应变时效过程中没有明显沉淀析出物,其时效硬度下降是固溶度降低、残余应力消除以及回复与再结晶的结果;而Ni与Fe质量比为9/1的合金经预应变时效后析出了细小弥散的β相,其硬度变化存在两种机制,一种是固溶度降低、残余应力消除和回复与再结晶引起软化,另一种是细小β相沉淀析出导致弥散强化。更多还原

【Abstract】 The hardness variation of two kinds of alloys with 36% tungsten content and 7/3, 9/1 nickeltoiron mass ratios during strain aging at 800 ℃ was studied. The microstructures of the aged alloys were analyzed by XRD and TEM. The results show that the strain aging hardness of WNiFe ternary alloy with 7/3 nickeltoiron mass ratio decreases monotonically with the increase of aging time. Under the same conditions, however, the hardness of 9/1 nickeltoiron mass ratio alloy decreases in the initial aging stage, and then increases as aging process goes on. XRD and TEM analysis show that there isnt any precipitation depositing from the alloy with 7/3 nickeltoiron mass ratio during aging. The monotonic decrease in hardness of this alloy during aging process results from the recovery, recrystallization and solid solubility declining. In the alloy of 9/1 nickeltoiron mass ratio, the fine β phase precipitates dispersively during aging. Therefore, there are two different kinds of mechanisms influencing the hardness of the alloy with 9/1 nickeltoiron mass ratio, one is recovery, recrystallization and solid solubility declining course, which softens the alloy, and the other one is the dispersion strengthening effect induced by the deposition of β phase, which hardens the alloy. These two mechanisms result in the hardness variation of the alloy with 9/1 nickeltoiron mass ratio as mentioned above.更多还原