Study On The Properties Of Molybdenum-based High Temperature Molds By Powder Metallurgy Press Forming

High temperature extrusion of copper and copper alloy,aluminium and aluminium alloy to the requirement of mould,in order to improve the die life,so the need to develop a kind of new material,the molybdenum powder metallurgy material,it is a kind of foreign markets emerging has high hardness,high temperature wear resistance,high temperature tensile strength,resistance to high temperature,high pressure and strong corrosion resistance and other excellent performance of new high temperature mold materials.Literature and research shows that: to the high temperature alloy add right amount of Al₂O₃,La₂O₃ and C can improve and enhance molybdenum base some key process performance of high temperature alloy,such as hardness,wear resistance and oxidation resistance,etc.This experiment is the main research to Mo-W-Co is added respectively in the high temperature alloys with different mass fraction of Al₂O₃,La₂O₃ and C on the microstructure and properties research,get a optimal process performance material;Later,the metal with the material and add elements of mixed powder by high-energy planet mill,according to the manufacturer to provide product drawings to design a set of reasonable steel mold,then powder compacting,obtaining the required product mould YuanPi;Getting products mold vacuum sintering,surface treatment;Finally test the product mould process performance.Experimental idea is to achieve high temperature molybdenum base mold used in factory as the goal,to study and get a Mo-W-Co-X optimal high temperature alloy.In this paper,the conclusions are as follows:?1?The research and selection of high temperature alloy Mo-W-Co-X?X as Al₂O₃,La₂O₃,or C?of a material in the process of optimal performance,and the material as the raw material of mould products.?2?According to the manufacturers to provide products mold drawings,design their own a set of reasonable steel mould,the research and analysis of powder pressing forming process,the calculation under the condition of this experiment theory to suppress the size of the pressure and analysis suppress the factors in the process of the injection mold product forming effect.?3?Using powder extrusion forming Huang Peiyun double logarithm equation calculation in the process of press forming pressing pressure,pressure of theory and practical comparison showed that Huang Peiyun log-log powder extrusion forming equation calculating the size of the pressure in accordance with the actual pressure.Vacuum sintering can well improve the density and hardness of the compact,when presintering temperature is 1240 ?,4 h,burning temperature is 1460 ?,2 h,improve the best effect.?4?After forming green compacts were sintered,of sintered compacts of plasma carburizing and sputtering Cr film surface treatment,mold performance testing,results show that: the mold surface treatment methods improve the product mold surface is bright and clean degree.And improve the surface hardness,high temperature wear resistance and high temperature oxidation performance and other technological properties,greatly extend the service life of the mold.