The influence of density of pressed iron powder samples on the quality of boride layers

Abstract

In this work the influence of the density of pressed iron powder on the quality of boride layers has been analysed. Examinations were performed on pressed samples of iron powder. The used granulation was 50-100, 100-150 and 150-200 mm. The samples were pressed under pressure of 200, 400, 600, 800 and 1000 MPa. Boroning was performed in a solid mixture based on boron-carbide, and was in principle the same for all samples. The obtained boride layers varied in depth and quality (porosity, the contact with metal). It has been observed that simultaneously with boroning sintering also occurred, and this fact offers a wide application possibility in the chemical-thermal treatment for sintered materials

The Structure and Properties of Boride Coatings Depending on the Porosity of Powder Steel Preforms

“…The boriding of powder steels has unique features. In particular, the effect of increasing the coating thickness during boriding of porous blanks (compared with compact steels of similar composition) was noted in our previous work [8] and in [9,10]. Apparently, it is due to the large surface porosity of the powder billets promoting a deeper penetration of boron atoms.…”

Optimization of the aging regime of Al-based alloys

“…Metod simpleks-planova omogućava dobijanje složenih modela istraživanih zavisnosti [7][8][9][10]. Ovo je naročito važno, jer su linearni ili kvadratni modeli retko kad adekvatni pri variranju temperature i vremena u širokim granicama, a primena faktornih planova u cilju dobijanja modela trećeg ili viših stepena zahteva suviše veliki broj eksperimenata [5,6,[13][14][15][16][17][18][19].…”

“…a ispitivana veličina se tada može izraziti regresionim polinomom [5,6,[13][14][15][16][17][18][19]. Koristeći se ovim uslovom, regresioni polinom se može uprostiti smanjenjem broja koeficijenata regresije tako da će biti potreban manji broj rezultata za njihovo određivanje.…”

The possibility of the boronizing process on the pressed samples of iron powder

“…Za eksperimentalna istraživanja predstavljena u ovom radu, izabran je sastav smeše za boriranje, aktivatori, pritisak presovanja, temperatura i vreme boriranja [6]. Takođe je izvršena karakterizacija železnog praha, homogenizacija smeše prahova za boriranje, presovanje uzoraka, karakterizacija otpresaka (tabele 1 i 2), boriranje otpresaka od železnog praha i karakterizacija boriranih uzoraka (tabele 1 i 2), sa ciljem da se utvrdi mogućnost procesa boriranja presovanih uzoraka od železnog praha uz i istovremeno sinterovanje.…”