(1. 河南科技大學(xué) 材料科學(xué)與工程學(xué)院，洛陽 471003;
2. 河南科技大學(xué) 河南省有色金屬材料科學(xué)與加工技術(shù)重點(diǎn)實(shí)驗(yàn)室，洛陽 471003)
摘 要: 采用Gleeble−1500D熱模擬試驗(yàn)機(jī)，在溫度為650~950 ℃、應(yīng)變速率為0.01~5 s−1、總應(yīng)變量為0.7的條件下，對25%W-Cu和50%W-Cu(質(zhì)量分?jǐn)?shù))復(fù)合材料的熱變形行為及其熱加工圖進(jìn)行研究和分析。結(jié)果表明：此兩種復(fù)合材料的高溫流動應(yīng)力—應(yīng)變曲線主要以動態(tài)再結(jié)晶為特征，峰值應(yīng)力隨變形溫度的降低或應(yīng)變速率的升高而增大；在真應(yīng)力—應(yīng)變曲線基礎(chǔ)上建立的W-Cu復(fù)合材料高溫變形本構(gòu)模型較好地表征了其高溫流變特性；同時(shí)，利用50%W-Cu復(fù)合材料DMM加工圖分析了其變形機(jī)制和失穩(wěn)機(jī)制，確定其熱加工工藝參數(shù)應(yīng)優(yōu)先選擇變形溫度為650~700 ℃、應(yīng)變速率為1~5 s−1，或者變形溫度為850~950 ℃、應(yīng)變速率為0.01~0.1 s−1。
關(guān)鍵字: W-Cu復(fù)合材料；應(yīng)變速率；峰值應(yīng)力；動態(tài)再結(jié)晶；加工圖
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China;
2. Henan Key Laboratory of Advanced Non-Ferrous Materials, Henan University of Science and Technology,
Luoyang 471003, China）
Abstract:Using the Gleeble−1500D simulator, the high-temperature plastic deformation behavior and processing map of 25%W-Cu and 50%W-Cu (mass fraction) composites were investigated at 650−950 ℃ with the strain rate of 0.01−5 s−1 and total strain of 0.7. The results show that the softening mechanism of the dynamic recrystallization is a feature of high-temperature flow stress—strain curves of the two composites, and the peak stress increases with the decrease of deformation temperature or the increase of strain rate. Based on the true stress—strain curves, the established constitutive equation represents the high-temperature flow behavior of W-Cu composite, and the calculated results of the flow stress are in good agreement with the experimental results of the high-temperature deformation of the two composites. Meanwhile, the obtained processing map of dynamic material modeling is used to analyze the deformation mechanism and the destabilization mechanism of 50%W-Cu composite, the optimal deformation processing parameters of the deformation temperatures range and the strain rates range are 650−700 ℃ and 1−5 s−1 or 850−950 ℃ and 0.01−0.1 s−1, respectively.
Key words: W-Cu composite; strain rate; peak stress; dynamic recrystallization; processing map
