PRODUCTION OF HIGH FRACTURE TOUGHNESS AND HIGH FATIGUE STRENGTH BULK METALLIC GLASSES AND EXAMINATION OF THE MECHANISM

单相（SF）块状玻璃合金（BGAs）和纳米晶体管（NC）的一些Zr、Cu和Pd系统的EGAs已被某些制造方法合成。在哪里，NC BGA是玻璃合金，其中包含纳米尺度晶体管颗粒嵌入均匀地嵌入玻璃矩阵中。然后对这些BGA进行了测试，硬度极限的比率（σ_w;一半为全压力强度）低于0.1至张力强度（σ_B）的压力比率（σ_B），显示了15%（σ_B =1.7 GPa）的值，这大约三次与相同组合的SF BGA的比率进行了比较。在Cu-based BGA exhibited a very large value of 24%（σ_B =2.0 GPa）的比率。这些σ_w为应用程序提供了足够的价值。It is thought that the drastic rise in the\_w of these NC BGAs is derived from the prevention of slip initiation and propagation by the NC particles。A Zr-based BGA with a high degree of amorphousness exhibited a fracture touness value （Kic） of 53 MPa·m^<1/2\。它被澄清，因为基于Zr-based BGA有一个有效的Kic可供实际使用。一个基于Zr-based NC BGA和假定结晶化的Zr-based BGA的最大值为40和11 MPa·m^<1/2>，相应地。这就是为什么我想通过水晶化来实现嵌入：基于Pd的SF BGA不可能有脂肪裂纹，并且在同一时间在三个或多个方向上传播有缺陷的缺陷显示36兆帕·m^<1/2>和裂纹的价值。An estimated K/c showed a small value of 1/2 MPa·m^<1/2\。

Single phase (SF) bulk glassy alloys (BGAs) and nanocrystalline (NC) EGAs of some Zr-, Cu- and Pd-based systems have been synthesized by some fabrication methods. Where, the NC BGA is the glassy alloy which contain nano-scale crystalline particles embedded homogeneously in glassy matrix. Then fatigue strength and fracture toughness in these BGAs were examined.The ratio of fatigue limit (σ_w ; half a full stress amplitude) under stress ratio of 0.1 to tensile strength (σ_B) of the Zr-based NC BGA showed a value of 15% (σ_B=1.7 GPa), and it was approximately three times larger compared with the ratio of the SF BGA of the same composition. The ratio of σ_w to σ_B of the Cu-based BGA exhibited a very large value of 24% (σ_B=2.0 GPa). These σ_w s show the enough values for applications. It is thought that the drastic rise in the σ_w of these NC BGAs is derived from the prevention of slip initiation and propagation by the NC particles.A Zr-based BGA with a high degree of amorphousness exhibited a fracture touness value (Kic) of 53 MPa・m^<1/2>. It was clarified that the Zr-based BGA has a sufficient Kic for practical uses. The Kic s of a Zr-based NC BGA and considerably crystallized Zr-based BGA were small even in the maximum value with 40 and 11 MPa・m^<1/2>, respectively. This is thought to be due to the embrittlement by the crystallization.The Pd-based SF BGA could not have fatigue cracks, and the value of notched fracture toughness exhibit 36 MPa・m^<1/2> and cracks propagated in three or more directions at the same time. An estimated K/c showed a small value of 12 MPa・m^<1/2>.