【摘要】：傳統(tǒng)合金體系均以一種或者兩種元素為主,合金的性質受制于主元素,且傳統(tǒng)合金設計理念認為合金系統(tǒng)中主元數(shù)越多,則越易形成金屬間化合物等復雜相,因而會使合金的性能惡化并使合金元素作用的分析變得困難。高熵合金作為了一種新型合金,突破了傳統(tǒng)合金的設計理念,采用五種或五種以上元素按照等摩爾比或近等摩爾比進行混合而成,提高合金混合熵,促進固溶體的形成,有時會形成金屬間化合物,甚至是非晶相,強化合金性能。本文選用Al、Fe、Ti、Cr、Ni、Zr、W、Mo和Nb九種元素中的幾種元素按等摩爾比來配置合金,利用非自耗電弧熔煉爐熔煉,熔煉了FeTiNbMo W、FeCr NiMo NbW、FeTiCrNiMoNbW、AlFeCrNiMo NbW和TiZr Mo NbW五種高熵合金,采用SEM、EDS及XRD等方法對高熵合金進行組織形貌、相結構進行了分析,并分別對合金的密度,宏觀、微觀及退火的硬度及壓縮性能進行測試。實驗結果表明:FeTiCrNiMoNbW和TiZrMo NbW高熵合金形成了簡單固溶體結構,其他幾種合金均由簡單固溶體和金屬間化合物組成,FeTiNbMo W、FeCrNiMo NbW、FeTiCrNiMoNbW和AlFeCrNiMo NbW高熵合金的組織形貌均為典型的樹枝晶形貌,而TiZr Mo NbW高熵合金為棉絮狀組織。五種高熵合金的實測密度均大于理論密度,且高熵合金的洛氏硬度在HRC 54.5~HRC 66.8之間,樹枝晶的顯微硬度大于枝晶間,棉絮組織硬度大于棉絮間,合金的退火硬度均高于其鑄態(tài)硬度,其中FeTiCr NiMo NbW和AlFeCrNiMo NbW合金在1200℃出現(xiàn)了退火軟化現(xiàn)象。五種合金壓縮強度在563.35MPa~2426.91MPa之間,斷裂形式均為解理斷裂,其中TiZrMo NbW高熵合金的性能做好。
[Abstract]:Traditional alloy systems are dominated by one or two elements, and the properties of alloys are restricted by the principal elements, and the traditional alloy design concept holds that the more principal components in the alloy system, the easier it is to form complex phases such as intermetallic compounds. As a result, the properties of the alloy will deteriorate and the analysis of the effect of the alloy elements will be difficult. As a new type of alloy, high entropy alloy has broken through the design idea of traditional alloy. Five or more elements are mixed according to equal molar ratio or near equal molar ratio to improve the mixing entropy of alloy and promote the formation of solid solution. Sometimes intermetallic compounds, even amorphous phases, are formed to strengthen the properties of the alloy. In this paper, five kinds of high entropy alloys, FeTiNbMo Wy FeCr NiMo NbW,FeTiCrNiMoNbW,AlFeCrNiMo NbW and TiZr Mo NbW, are melted in non-consumable arc melting furnace by using several elements of Al,Fe,Ti,Cr,Ni,Zr,W,Mo and Nb in equal molar ratio. The microstructure and phase structure of the high entropy alloy were analyzed by SEM,EDS and XRD. The hardness and compressive properties of the alloy were tested by means of density, macroscopical, microcosmic and annealed. The experimental results show that FeTiCrNiMoNbW and TiZrMo NbW high entropy alloys form a simple solid solution structure, and the other alloys are composed of simple solid solution and intermetallic compounds. The microstructure of both FeTiNbMo WGuFeCrNiMo NbW,FeTiCrNiMoNbW and AlFeCrNiMo NbW high entropy alloys are typical dendritic morphology. TiZr Mo NbW high entropy alloy is cotton-like structure. The measured densities of the five kinds of high entropy alloys are all higher than the theoretical densities, and the Rockwell hardness of the high entropy alloys is in the range of HRC 54.5~HRC 66. 8, the microhardness of dendrite is greater than that of dendrite, and the microhardness of cotton flocs is greater than that of cotton floc. The annealed hardness of the alloy is higher than that of the as-cast alloy, and FeTiCr NiMo NbW and AlFeCrNiMo NbW alloys show annealing softening phenomenon at 1200 鈩，

本文編號：2213623