Effect of Wax Addition on Monel Synthesis by High Energy Milling

Study on the Role of Stearic Acid and Ethylene-bis-stearamide on the Mechanical Alloying of a Biomedical Titanium Based Alloy

“…Previous studies have also addressed the delay in the alloying process using different types of PCA. [15,18,24] In the present study, no alloying could be observed when the MA was processed with 3 pct SA or EBS for 5 hours, as shown in Figures 1(c) and (f). This fact is due to the reduction in surface tension of the solid materials by absorption of the PCA, leading to a lower degree of cold welding.…”

“…On the other hand, the PCA acts as a physical barrier and increases the interdiffusion distance between powder particles, making the particles incapable of contacting each other with fresh surfaces; thus, atoms cannot be transferred through one surface of a particle to another. According to Rocha et al, [18] the PCA could also absorb part of the energy induced by the colliding balls and suppress the cold welding mechanism.…”

“…Among the most commonly used PCAs in the MA process are stearic acid (SA) [10,11] and ethylene-bis-stearamide (EBS). [12][13][14] Although a number of investigations have studied the effect of PCA on the microstructure, morphology, and thermal properties of powders after MA, [10,13,[15][16][17][18][19][20][21] little attention has so far been given to the understanding of the microstructure of bulk sintered alloys and to the establishment of a link between the microstructures and the different contents of the PCA. The present study aims to investigate the effect of different SA and EBS additions on the microstructural evolution of powder and bulk sintered biocompatible Ti-16Sn-4Nb (wt pct, hereafter) alloy for a relatively short period of ball milling time of 5 hours.…”

Influência de agentes controladores de processo na síntese por combustão mecanicamente ativada do NbAL3

“…Em outros trabalhos (Lu e Zhang, 1999;Rocha et al, 1999), reportou-se que durante a moagem reativa, a quantidade do agente (no caso o ácido esteárico) pode afetar a cinética da reação, provocando uma diminuição na velocidade de formação da liga com a adição de uma maior quantidade de ACP.…”

“…Outra explicação fornecida para tal fato refere-se a uma possível diminuição de parte da energia mecânica necessária para o processo de soldagem, em conseqüência da absorção dessa energia pelo agente (Rocha et al, 1999).…”