Effect of La₂O₃on microstructure and properties of Cu₂₀Fe₈₀alloy by microwave sintering

Abstract

Abstract. It was prepared that Cu 20 Fe 80 alloys using the mechanical alloying and cold pressing and the microwave sintering. The microstructure and the phase composition of Cu 20 Fe 80 alloy were analyzed by SEM and XRD, respectively. The density and hardness of the alloys were measured. The effect of La 2 O 3 on microstructure and properties of Cu 20 Fe 80 alloy was investigated during the microwave sintering. The results have shown that the powder milling structure of Cu 20 Fe 80 alloy is a flake layer which is refined and the mechanical alloying enhanced with increasing La 2 O 3 content; The microstructure of the Cu 20 Fe 80 alloy powder blank cold pressed is lamellar which gradually become dense, the density increases and the formability is improved with the increase of La 2 O 3 content; The microstructure of the Cu 20 Fe 80 alloys sintering was lamellar that the voids and the density and the hardness change with the increase of La 2 O 3 content and the best La 2 O 3 content was 0.2%. IntroductionIron -Copper -based powder metallurgy bearing material, which can save non-ferrous metals and reduce the cost of raw materials [1][2][3]. But the traditional bearing mixed iron copper powder, the compressive strength, hardness is based on copper based materials on the increased slightly, poor corrosion resistance, and will inevitably generate and microstructure segregation caused by inhomogeneity of hard phase and the performance of the resulting running noise increases and shorten the service life of the bearing, the in the large-scale automation production process, is not conducive to ensure the consistency and stability of the product performance [4][5][6][7] . In this paper, La 2 O 3 was added in the preparation of Cu-Fe alloy, and the effect of La 2 O 3 on the microstructure and properties of Cu-Fe alloy during mechanical alloying and cold pressing microwave sintering was studied.

Effect of La on microstructures and mechanical properties of Cu/Ti3SiC2/C nanocomposites sintered by vacuum hot-pressing and hot isostatic pressing

“…Zhang et al [27] studied the mechanical properties of Cu composites, and the hardness of the composites showed a significant improvement, from 135 HV to 140 HV, mainly due to the addition of La to refine and disperse other particles. Fu et al [28] studied the effect of La 2 O 3 on the microstructure and properties of Cu alloys, and found that when the content of La 2 O 3 increased to 0.2%, the hardness reached a maximum. When the La content is too large, the alloy structure exhibits thick black and gray flakes, the distribution is uneven, and the surface also contains a large number of pores, and the relative densities and hardness of the alloy are lowered.…”

“…The results in figure 6(b) show that the shear strength of the composites is not significantly improved. In general, composite interface bonding can be divided into four types: mechanical bonding, physical bonding (Van Der Waals interaction), diffusion bonding, and reaction bonding, and the binding forcesare sequentially increased [28]. Most of the reinforcing phases such as Cu and CNP S are mechanically bonded together, and the bonding strength is low.…”

“…Moreover, during the stressing process of the composite material, the pleated structure of the CNP S is first flattened and then fractured, thereby exerting a buffering force effect. Chu et al [28] studied the strength of CNP S -Cu composites, suggesting that the addition of CNP S below 8 vol% can significantly increase the yield strength and Young's modulus to 114% and 37%, respectively. Because of the effective pinning effect of CNP S on the grain boundaries, dislocation motion can be prevented in the grain boundaries.…”