钨钼室温脆性的研究

来源期刊：中南大学学报(自然科学版)1986年第4期

论文作者：左铁镛

文章页码：46 - 53

关键词：脆性； 断口； 裂纹； 间隙杂质； 亚结构； 俄歇分析； 透视电镜； 扫描电镜； 钨； 钼； 晶界

Key words：Brittleness； Fracture surface； Crack； InterstitiaI impurities； Auger analysis； SEM； TEM； Tungsten； Oxygen； Grain boundaries

摘    要：对不同实验条件下制备的钨和钼的试样作扫描电镜、透射电镜和俄歇电子能谱分析。断口形貌分析表明,在室温下烧结态和再结晶态的断口呈典型的晶间脆性断裂,低形变及再结晶试样为晶间脆断和穿晶解理的混合型断裂,高度形变的试样断口呈纤维状韧性断裂特征,是纤维束撕裂、分层,而后单个纤维出现缩颈、微孔合并所致。在10^-9Torr高真空度下对新鲜断口作俄歇电子能谱分析证实,间隙杂质磷、氧和碳是钨的主要晶界杂质,而钾、氧和碳则在掺杂钨的晶界明显富集,可以确认这些在晶界大量富集的杂质是削弱晶界强度,造成钨钼室温脆性的基本原因.文中还分析了晶粒结构和亚结构对室温脆性的影响。

Abstract: The specimens of W and Mo with bcc structure were analyzed by scanning electronmicroscope, transmission electron microscope and Auger electron energy spectrum. An analysisof fracture surface indicated that the brittle intercrystalline rupture was the main wayin which the sintered and recrystallized W and Mo fail at room temperature, and that therewas also a mixture of cleavage and intercrystalline rupture in the lower deformed specimens.Highly deformed samples showed the character of the fibred ductile fracture. Auger analysis offracture surface proved that brittleness at room temperature resulted mainly from obviousgathering of interstitial impurities, P, O, N and C at grain boundaries. The present workalso analyzed the influences of both the grain structure and the substructure on the brittlenessof W and Mo at room temperature.