The Al₂O₃Reinforced Rare Earth Molybdenum Alloy And Research On Preparation Of Properties

Molybdenum and it’s alloys have the characteristics of high melting point, lowcreep speed at high temperature, high creep strength, low expansion coefficient, betterthermal conductive and good thermal shock resistance, high abrasion resistance andcorrosion resistant performance.As a high performance materials, it is used inaerospace, defense military, oil chemical industry, nuclear industry and so on. But themolybdenum have the disadvantages of poorer strength, toughness and hardness underthe high temperature, lower recrystallization temperature, n brittle fracturing easilyafter recrystallizatio, and higher brittleness under lower temperature, high temperatureof plastic-brittle transition. Molybdenum and it’s alloys has the poorer Processingperformance and the narrow application scope with these defects.This issue develop a molybdenum alloy with high temperature recrystallizationand creep resistance, low plastic-brittle transition temperature, low brittleness at roomtemperature increacing the material wear performance with rare earth oxides andAl₂O₃. Product Al₂O₃/La₂O₃/Mo mixed powder by sol-gel method the Molybdenumalloy was prepareding powder metallurgy. The research results is as follows:The La₂O₃/Al₂O₃/Mo mixed powder’s main ingredients are La₂O₃、Al₂O₃andMo. The molybdenum alloy’s ingredients are Mo、Al₂O₃、La₂O₃、La₂O₃·11Al₂O₃.The powder particles were more refined and the powder reunion phenomenonwere improved with the increasing of La₂O₃and Al₂O₃.The Al₂O₃have the effect ofrefining the molybdenum grain pinning on grain boundary.The density of composite material was declined with the increasing of Al₂O₃andLa₂O₃; The microhardness of composite material was declined with the increasing ofAl₂O₃but have not obviously linear relation with La₂O₃.The abrasion loss of composite material at500℃was lower at25℃; Theabrasion loss of composite material was declined with the increasing of Al₂O₃at thesame temperature. The friction coefficient of composite material varies gently at25℃. the frictioncoefficient of composite material was different at500℃. The friction coefficientdensity of composite material was declined with the increasing of load.The morphology of wear surface of composite material was main grooves andfurrows because of the abrasive planning at25℃. The depth and width of the furrowwas increased with the increasing of load. The number and depth of the furrow wasdeclined with the increasing of Al₂O₃.