(哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150080)
摘 要: 采用金相顯微鏡、透射電鏡和X射線衍射儀等研究Ti-15-3合金板材在交叉換向軋制過程中的組織演變規(guī)律和力學(xué)性能變化。結(jié)果表明：經(jīng)過5道次換向冷軋、厚度方向總變形量為80%的Ti-15-3合金板中，形成了間隔的纖維帶狀組織，其內(nèi)部形成了200 nm左右的亞微米級(jí)晶粒。纖維組織的形成過程分為3個(gè)階段，第一階段，在個(gè)別晶粒內(nèi)部形成局部剪切帶；第二階段，拉長(zhǎng)帶狀組織內(nèi)部平行排列的剪切帶相互交叉并逐漸碎化；第三階段，形成間隔的纖維組織，其內(nèi)部晶粒為亞微米級(jí)。在軋制變形中，經(jīng)1道次變形后，抗拉強(qiáng)度迅速升高到949 MPa，隨后抗拉強(qiáng)度最終緩慢增加至1 021 MPa。固溶態(tài)合金以每道次30%的壓下量經(jīng)過5道次換向冷軋并于450 ℃時(shí)效4 h后，抗拉強(qiáng)度為1 646 MPa。
關(guān)鍵字: Ti-15-3合金；冷軋；時(shí)效；力學(xué)性能
Ti-15-3 alloy during cold-rolling
（School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150080, China）
Abstract:The microstructure evolution and mechanical properties of Ti-15-3 alloy during cold rolling were investigated by optical microscopy, transmission electron microscopy and X-ray diffractometer. The results show that fibrous microstructure in which grains are refined to about 200 nm was formed in the sheet of Ti-15-3 alloy with total thickness reduction of 80% after five passes cross cold rolling. The structure formation may be divided into three steps: firstly, the partial shear bands form in some grains; secondly, the shear bands of different direction within the banded structure cross and refine; thirdly, the fibrous microstructure with sub-micron grains forms. During cold rolling, the ultimate strength of alloy increases sharply to 949 MPa after 1 pass and slightly to 1 021 MPa in the following passes. After 5 passes cross cold rolling with cold rolling rate of 30% per pass and aging at 450 ℃ for 4 h, the ultimate strength of alloy can be increased to 1 646 MPa.
Key words: Ti-15-3 alloy; cold rolling; aging; mechanical properties
