(中信戴卡股份有限公司, 秦皇島 066011)
摘 要: 采用鈦鹽與硼鹽反應(yīng)法成功制備原位自生TiB2/純Al復(fù)合材料。利用掃描電子顯微鏡、透射電子顯微鏡和拉伸試驗機研究不同粒子含量(質(zhì)量分數(shù)為1%、2%和3%)對復(fù)合材料組織和力學(xué)性能的影響。結(jié)果表明：原位生成的TiB2粒子有矩形、近圓形和六邊形三種形貌，尺寸為200~500 nm；粒子與Al基體界面潔凈無反應(yīng)層。隨著粒子含量的增加，復(fù)合材料的強度隨之升高，而伸長率則隨之降低；當TiB2含量為3%時，屈服強度和抗拉強度分別達到78.1 MPa和102 MPa，相比于純Al分別提高58%和43%，而伸長率降至32.5%，下降了24%。斷口分析表明：隨著TiB2粒子含量的增加，粒子團聚機率增加，在拉伸過程中，裂紋在粒子團聚處萌生并擴展，導(dǎo)致材料的塑性降低。
關(guān)鍵字: 復(fù)合材料；TiB2顆粒；力學(xué)性能；組織
（CITIC Dicastal Co., Ltd., Qinhuangdao 066011, China）
Abstract:The in-situ TiB2/pure Al composites were fabricated successfully by titanium salt and boron salt reaction process. The influences of TiB2 contents (1%, 2% and 3%, mass fraction) on microstructure and mechanical properties were studied by scanning electronic microscopy, transmission electronic microscopy and tensile test machine. The results show that the morphologies of TiB2 particles present in rectangular, nearly rounded and hexagonal with the size of about 200-500 nm. And the interface between TiB2 particles and Al matrix is clean. Tensile test results indicate that the strength significantly increases while the elongation decreases with the increasing of TiB2 particles. The yield strength (YS) and ultimate tensile strength (UTS) of TiB2/pure Al composite at 3% TiB2 particles reach 78.1 MPa and 102 MPa, respectively, while the elongation reduces to 32.5%. The composite has achieved 58% and 43% improvement, respectively, in YS and UTS with respect to pure Al, while compromising 24% in ductility. The fractography reveals that agglomerations happen severely with increasing the TiB2 particles amounts, and the crack propagation tends to begin from the agglomerations, which leads to the decreasing of ductility.
Key words: composites; TiB2 particles; mechanical property; microstructure
