(南昌航空大學(xué) 輕合金加工科學(xué)與技術(shù)國防重點(diǎn)學(xué)科實(shí)驗(yàn)室，南昌 330063)
摘 要: 采用攪拌摩擦加工(FSP)方法對添加不同聚四氟乙烯(PTFE)含量混合粉末(PTFE+Ni)制備Ni/Al復(fù)合材料。采用SEM、EDS、XRD及EPMA對復(fù)合區(qū)微觀組織進(jìn)行分析，采用室溫拉伸試驗(yàn)對Ni/Al復(fù)合材料力學(xué)性能進(jìn)行測試。結(jié)果表明：在一定范圍內(nèi)，隨著PTFE含量的增加，Ni/Al復(fù)合材料的均勻性逐漸提高，且增強(qiáng)相生成量逐漸增加；當(dāng)PTFE含量達(dá)到7%時(shí)，其拉伸強(qiáng)度達(dá)到233 MPa，較添加純鎳制備Ni/Al復(fù)合材料拉伸強(qiáng)度(163 MPa)提升了42.9%；當(dāng)PTFE含量超過7%時(shí)，部分PTFE裂解放出大量的熱量，使得Al與PTFE發(fā)生反應(yīng)生成AlF3和不同的鋁化物，導(dǎo)致局部Al-Ni反應(yīng)過程中Al含量不足，部分Ni未反生反應(yīng)，減少了Al3Ni金屬間化合物生成物的數(shù)量，使得拉伸強(qiáng)度下降。
關(guān)鍵字: 攪拌摩擦加工；PTFE；復(fù)合材料；原位反應(yīng)
（National Defence Key Discipline Laboratory of Light Alloy Processing Science and Technology, Nanchang Hangkong University, Nanchang 330063, China）
Abstract:Ni/Al composites were fabricated by friction stir processing (FSP) through adding different amounts of (PTFE+Ni) mixed powders to Al substrate. The microstructures of the composite zone were analyzed by SEM and EDS, the phase composition was examined by XRD, the element distributions of the composite zone were analyzed by EPMA, and the mechanical properties of the composites were tested by tensile test at room temperature. The results show that, within a certain range, the uniformity of composites increases with increasing the amount of PTFE and the number of Al3Ni intermetallic compound will be increased. When PTFE content reaches 7%, the tensile strength of composites reaches 233 MPa, compared with the composites with pure Ni (its tensile strength is 163 MPa), the tensile strength of composites with 7% PTFE increases by 42.9%; when PTFE content exceeds 7%, the reaction degree between Al and Ni increases because the PTFE cracked will produce lots of heat, at the same time, different aluminide and AlF3 are produced. The agglomerations of Ni are found because the amount of partial Al decreases. As the reaction degree between Al and Ni decreases, the number of Al3Ni intermetallic compounds decreases, as well as the tensile strength.
Key words: friction stir processing; PTFE; composites; in-situ reaction
