(中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙410083)
摘 要: 對(duì)鍛造純Mo棒進(jìn)行不同變形量的鐓粗加工，觀察其在此過(guò)程中的室溫橫向彎曲性能和織構(gòu)演變。結(jié)果表明：鍛造變形85%的純Mo棒的橫向彎曲伸長(zhǎng)率僅為0.5%，經(jīng)鐓粗變形其橫向塑性得到提高；鐓粗變形50%和85%后，伸長(zhǎng)率分別達(dá)到1.5%和5.0%，其原因是在純Mo棒中形成的縱向伸長(zhǎng)的纖維組織被橫向扭曲，且晶粒間相互穿插，這種組織由<011>織構(gòu)的組織演變而來(lái)；鍛造Mo棒中形成<011>纖維織構(gòu)，這種織構(gòu)對(duì)Mo棒的橫向塑性不利，經(jīng)鐓粗變形，<011>纖維織構(gòu)轉(zhuǎn)變?yōu)?lt;001>和<111>纖維織構(gòu)；鍛態(tài)Mo棒的斷裂方式為沿晶斷裂，鐓粗變形后，斷裂方式主要為穿晶斷裂；斷口還發(fā)現(xiàn)有“分層韌化”現(xiàn)象出現(xiàn)。
關(guān)鍵字: 純Mo棒；鐓粗；橫向塑性；織構(gòu)；沿晶斷裂；穿晶斷裂
pure molybdenum bars in upset process
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The transverse elongations and textures of pure molybdenum bars manufactured by upset with different amounts of deformation were investigated at room temperature. The results show that the transverse elongation of the forged Mo bars with 85% deformation is 0.5%, which is greatly improved by the upset process. By upset with 50% and 85% deformations, the transverse elongations of the bars are only 1.5% and 5.0%, respectively, because the fiber structures in the longitudinal direction are distorted along with the transverse direction and interpenetrate each other, and these structures are developed from <011> fiber; which has a bad effect on the transverse ductility of the forged Mo bars. After the upset deformation, the fiber texture of <011> changes to <001> and <111>. The fracture mode changes from intergranular to a transgranular and shows a ductile laminate fracture mechanism.
Key words: pure molybdenum bar; upset; transverse ductility; texture; intergranular fracture; transgranular fracture
