(1. 中南大學(xué) 粉末冶金國家重點實驗室，長沙 410083；
2. 香港城市大學(xué) 材料科學(xué)與工程系，香港 999077)
摘 要: Ti基金屬-金屬復(fù)合材料具有良好的強度和塑性等綜合性能。采用掃描電子顯微術(shù)(SEM)、X射線衍射(XRD)、材料力學(xué)性能試驗、分離式霍普金森壓桿(SHPB)、MATALAB軟件等分析技術(shù)研究了W顆粒增強Ti基金屬-金屬復(fù)合材料(Ti-W)在準(zhǔn)靜態(tài)和動態(tài)下的力學(xué)行為。結(jié)果表明：Ti-W復(fù)合材料具有β-Ti相和β-W相組成的雙相異質(zhì)結(jié)構(gòu)；當(dāng)W元素含量大于25%(摩爾分數(shù))時，組織中析出細小的富W相。Ti-W復(fù)合材料在準(zhǔn)靜態(tài)下的最高屈服強度和極限強度可達1567 MPa(Ti-30W)和1726 MPa(Ti-30W)；動態(tài)下最高屈服強度和極限強度可達2148 MPa(Ti-15W)和2908 MPa(Ti-30W)。因此，Ti-W復(fù)合材料具有明顯的應(yīng)變速率強化效應(yīng)。比較了改進的Johnson-Cook(JC)本構(gòu)模型和Back-Propagation(BP)神經(jīng)網(wǎng)絡(luò)模型對Ti-W復(fù)合材料力學(xué)行為的適用性，發(fā)現(xiàn)BP神經(jīng)網(wǎng)絡(luò)能更好地描述Ti-W復(fù)合材料在準(zhǔn)靜態(tài)和動態(tài)下的力學(xué)行為。
關(guān)鍵字: Ti-W金屬-金屬復(fù)合材料；應(yīng)變速率強化；Johnson-Cook(JC)本構(gòu)模型；Back-Propagation(BP)神經(jīng)網(wǎng)絡(luò)模型
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong 999077, China）
Abstract:Ti matrix metal-metal composites exhibit good comprehensive properties such as strength and plasticity. The quasi-static and dynamic behavior of W particle reinforced Ti matrix metal-metal composites(Ti-W) were investigated by scanning electron microscopy(SEM), X-ray diffractometry (XRD), material mechanical properties test, split Hopkinson pressure bar (SHPB) and MATALAB software. The results show that Ti-W composites exhibit a dual phase heterostructure composed of β-Ti and β-W. When the content of element W in the composite is greater than 25% (mole fraction), fine W-rich phase is precipitated in the tissue. The maximum yield strength and ultimate strength of Ti-W composites can reach 1567 MPa (Ti-30W) and 1726 MPa (Ti-30W) under quasi-static condition. The maximum yield strength and ultimate strength can reach 2148 MPa (Ti-15W) and 2908 MPa (Ti-30W) under dynamic condition. Therefore, Ti-W composites exhibit obvious strain strengthening effect. By comparing the applicability of the modified Johnson-Cook (JC) constitutive model and Back-Propagation (BP) neural network model to the mechanical behavior of Ti-W composites, it is found that BP neural network can better describe the quasi-static and dynamic behavior of Ti-W composite.
Key words: Ti-W metal-metal composite; strain rate strengthening; Johnson-Cook (JC) constitutive model; Back-Propagation (BP) neural network model
