Ti70Nb7.8Cu8.4Ni7.2Al6.6復合材料
(華南理工大學 國家金屬材料近凈成形工程技術研究中心，廣州 510640)
摘 要: 采用機械合金化制備不含和含2%(體積分數(shù))B4C的鈦基非晶合金粉末，隨后采用放電等離子燒結(jié)−非晶晶化法合成不含/含(TiB+TiC)的Ti70Nb7.8Cu8.4Ni7.2Al6.6超細晶/細晶鈦基復合材料；運用X射線衍射分析(XRD)、差示掃描量熱分析(DSC)、掃描電子顯微鏡(SEM)和萬能材料試驗機等對制備的鈦基非晶粉末和超細晶/細晶鈦基復合材料進行表征。結(jié)果表明：高能球磨80 h的鈦基粉末中主要為非晶相，B4C顆粒的加入對鈦基粉末的玻璃轉(zhuǎn)變溫度、晶化溫度和晶化焓有顯著的影響。另外，不含/含(TiB+TiC)的復合材料的顯微硬度分別為5.47和5.33 GPa；以50 K/min升溫到1 223 K并保溫10 min獲得的Ti70Nb7.8Cu8.4Ni7.2Al6.6塊體試樣的斷裂強度和斷裂應變分別為2 098 MPa和11.5%。
關鍵字: 鈦基復合材料；放電等離子燒結(jié)；機械合金化；晶化
（National Engineering Research Center of Near-net-shape Forming for Metallic Materials,
South China University of Technology, Guangzhou 510640, China）
Abstract:The Ti-based amorphous alloy powders without or with 2% (volume fraction, %) B4C were synthesized by mechanical alloying, and subsequently the powders were consolidated into crystallized Ti70Nb7.8Cu8.4Ni7.2Al6.6 ultrafine/fine-grained composites without or with (TiB+TiC) phases by spark plasma sintering and crystallization of amorphous phase. The synthesized powders and the consolidated ultrafine/fine-grained composites were examined by X-ray diffractometry (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and universal materials tester. The results show that, after a milling time of 80 h, the synthesized powders consist of amorphous phase with predominant volume fraction. The addition of B4C particles has an obvious impact on the glass transition temperature, crystallization temperature and crystallization enthalpy for the synthesized powders. In addition, the microhardnesses of the consolidated composites without or with 2% B4C are 5.47 and 5.33 GPa, respectively. Meanwhile, the consolidated Ti70Nb7.8Cu8.4Ni7.2Al6.6 composite by heating to 1 223 K at 50 K/min and holding for 10 min has a high fracture strength of 2 098 MPa and a fracture strain of 11.5%.
Key words: Ti-based composite; spark plasma sintering; mechanical alloying; crystallization
