(1. 河南科技大學 材料科學與工程學院，洛陽 471003;
2. 河南科技大學 河南省有色金屬材料科學與加工技術重點實驗室，洛陽 471003)
摘 要: 采用Gleeble−1500D熱模擬試驗機，在溫度為650~950 ℃、應變速率為0.01~5 s−1、總應變量為0.7的條件下，對25%W-Cu和50%W-Cu(質量分數(shù))復合材料的熱變形行為及其熱加工圖進行研究和分析。結果表明：此兩種復合材料的高溫流動應力—應變曲線主要以動態(tài)再結晶為特征，峰值應力隨變形溫度的降低或應變速率的升高而增大；在真應力—應變曲線基礎上建立的W-Cu復合材料高溫變形本構模型較好地表征了其高溫流變特性；同時，利用50%W-Cu復合材料DMM加工圖分析了其變形機制和失穩(wěn)機制，確定其熱加工工藝參數(shù)應優(yōu)先選擇變形溫度為650~700 ℃、應變速率為1~5 s−1，或者變形溫度為850~950 ℃、應變速率為0.01~0.1 s−1。
關鍵字: W-Cu復合材料；應變速率；峰值應力；動態(tài)再結晶；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
