Papers by Keyword: Instrumented Impact Test

Abstract: The ingots were rolled by 550 mills in laboratory to obtain dual-phase steels. The influence of the morphology and distribution of ferrite and martensite on mechanical properties of dual-phase steel was investigated. The results indicated that some amount of acicular ferrite transformed in DP steel is available for decreasing the size and homogenizing the distribution of martensite in ferrite base. Meanwhile, the values of yield strength, tensile strength and impact toughness increases apparently, the value of elongation decreases to 22.5% .

Abstract: A comprehensive experimental and theoretical work aiming at studying the dynamic failure process of silicon nitride ceramics has been recently started. The main goal of this research programme consists in characterizing the mechanical behaviour of the material under dynamic loading as well as investigating the dynamic failure process using micro- and macro-fractography. The current paper deals with the phenomenon of special rate dependence of KId dynamic fracture toughness of Si3N4 based ceramics. The KId values have been determined during instrumented impact test on the one hand based on the dynamic key curve method using notched specimens, on the other hand based on fractographic analyses of fracture surface of impacted unnotched samples.

Abstract: Chemical and structural changes at the grain boundaries were investigated to quantify their influence on fracture behaviour of austenitic stainless steels and model ferritic Fe-Si-P alloys. The balance between the size and the area density of intergranular particles was found to be one of the most decisive factors influencing sensitivity of the steels to intergranular fracture. The precise dependence of the energy of intergranular fracture on the phosphorus grain boundary concentration was also determined.

Abstract: The current paper give a brief overview over the principle and information content of the instrumented impact test completed by electro-emission measurement. Introducing over experiences taken by applying these test on a high-tech SiAlON ceramic a novel method for the determination of the dynamic fracture toughness of silicon nitride ceramics is suggested.