(1. 硬質(zhì)合金國家重點實驗室，株洲 412000；
2. 湖南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410082)
摘 要: 硬質(zhì)合金的服役環(huán)境通常十分惡劣，需要承受循環(huán)應(yīng)力、溫度(如高溫或循環(huán)溫度)和腐蝕環(huán)境的共同影響，機(jī)械疲勞、熱疲勞和腐蝕疲勞等多種疲勞斷裂機(jī)制是導(dǎo)致硬質(zhì)合金材料失效的重要原因。從疲勞裂紋的萌生和擴(kuò)展兩方面系統(tǒng)地闡述硬質(zhì)合金疲勞性能的影響因素。疲勞裂紋易沿著粗大的WC顆粒、孔洞、夾雜物和粘結(jié)相池等缺陷處萌生，而疲勞裂紋的擴(kuò)展行為受到各種因素的影響，如應(yīng)力比、頻率、溫度和環(huán)境等外部因素以及顯微結(jié)構(gòu)和化學(xué)成分等內(nèi)部因素。
關(guān)鍵字: 硬質(zhì)合金；疲勞裂紋；萌生；擴(kuò)展
（1. State Key Laboratory of Cemented Carbide, Zhuzhou 412000, China;
2. College of Materials Science and Engineering, Hunan University, Changsha 410082, China）
Abstract:Cemented carbides are often served in extreme environments, under which they need to suffer mutual influence of cyclic stress, temperature (such as high temperature and cyclic temperature) and corrosive environment. Various fatigue fracture mechanisms, such as mechanical fatigue, thermal fatigue and corrosion fatigue, are the main reasons for the failure of the alloys. In terms of the fatigue crack initiation and propagation, the fatigue performance in cemented carbide was systematically discussed. The analysis shows that the fatigue crack is prone to initiate at coarse WC grains, pores, inclusions or binder phase pools, while the propagation performance of fatigue crack is influenced by various factors, including external factors of stress ratio, frequency, temperature and environment, and internal factors of microstructure and chemical composition.
Key words: cemented carbide; fatigue crack; initiation; propagation
