Modelling of carbon nanotube dispersion and strengthening mechanisms in Al matrix composites prepared by high energy ball milling-powder metallurgy method

In the fabrication of nuclear reactor core parts, machining chips of Zircaloy are generated. These alloys are strategic for nuclear technology and cannot be discarded. In the present work are presented two methods for recycling of Zircaloy chips. One of the methods is by melting in VAR furnace and the other by powder metallurgy method. By this method the Zircaloy was submitted to hydriding process and milled in a high-energy ball mill. The powder was cold isostatically pressed and vacuum sintered. The elemental composition of the samples obtained by both ways was determined by XRF and compared to the specifications. The phase composition was determined by XRD. The microstructures resulting of both processing methods, before and after rolling were characterized using optical and scanning electron microscopy. The good results of the powder metallurgy method suggest the possibility of producing small parts, like cladding cap-ends, using near net shape sintering.

Download Full-text

Synthesis, microstructure, and mechanical properties of in situ TiB2/Al-4.5Cu composites

Science and Engineering of Composite Materials ◽

10.1515/secm-2015-0478 ◽

2018 ◽

Vol 25 (3) ◽

pp. 453-462 ◽

Cited By ~ 1

Author(s):

Hongying Li ◽

Shouxin Zhao ◽

Yangxun Ou ◽

Yongqiu Lai

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Yield Strength ◽

Particle Distribution ◽

Matrix Composites ◽

Strengthening Mechanisms ◽

Microstructure And Mechanical Properties ◽

Al Matrix Composites ◽

Al Matrix

Abstract In situ TiB2/Al-4.5Cu composites with different TiB2 particle amounts were fabricated by the salt-metal reaction technique. The effects of in situ TiB2 on the microstructure and mechanical properties of Al-4.5Cu alloy were studied in this paper. The results showed that in situ TiB2 particles had significant effect on refining grain size and improving mechanical properties of as-cast Al-4.5Cu alloy. With the amounts of TiB2 particles increasing, the yield strength and ultimate tensile strength were improved, while the elongation reduced. The strengthening mechanisms of the in situ particle-reinforcing Al matrix composites were discussed, and the yield strength was predicted accurately by accounting for the three strengthening mechanisms and particle distribution.

Download Full-text

Mechanical and Electrical Properties of Nano Al-Matrix Composites Reinforced with SiC and Prepared by Powder Metallurgy

Biointerface Research in Applied Chemistry ◽

10.33263/briac122.20682083 ◽

2021 ◽

Vol 12 (2) ◽

pp. 2068-2083

Keyword(s):

Mechanical Properties ◽

Electrical Conductivity ◽

Compressive Strength ◽

Electron Microscope ◽

Powder Metallurgy ◽

Relative Density ◽

Apparent Porosity ◽

Matrix Composites ◽

Al Matrix Composites ◽

Al Matrix

Nano Al-matrix composites reinforced with SiC were prepared by powder metallurgy process. The percentages of added SiC were varied between 0, 2, 4, 6, and 8 wt. %. The starting powders were milled in high-energy ball mill for 10hrs to convert into nanopowders; then compacted and sintered for 1h in an argon atmosphere at 400, 500, and 570°C. X-ray technique and transmission electron-microscope were utilized to examine the prepared powders, while scanning electron-microscope was utilized to test the sintered composites. The relative density, apparent porosity, electrical conductivity, and mechanical properties (microhardness, elastic moduli, and compressive strength) of sintered composites were studied. The results showed no sign for phase changes after milling, and the SiC reinforcement was uniformly distributed in the matrix. The relative density and electrical conductivity were decreased with increasing SiC content, while the apparent porosity was increased. It is also found that the mechanical properties were improved with increasing SiC content. Also, all properties were improved with increasing sintering temperature. The hardness, compressive strength, bulk modulus of Al-8wt.% SiC composite sintered at 570°C were 885.4 MPa, 276.2 MPa, and 135.9 GPa, respectively.

Download Full-text