Abstract
In view of increasing industrial interest in the use of tin additions as an aid to the sintering of iron-based powder compacts, an examination has been made of the influence of the characteristics of the tin powder on sintering performance.
The effect of additions of narrow size-range fractions of atomized tin powder on the dimensional changes and tensile properties obtained on sintering Fe-Sn-Cu compacts made with –100 mesh (–152 μm) or – 300 mesh (– 53 μm) sponge iron and – 300 mesh (– 53 μm) atomized copper powders has been determined. The compacts contained tin and copper in the ratio 2:3. The narrow size fractions were separated from – 300 mesh tin powder by air elutriation. It was found that the use of coarse tin powder reduced the tensile strength of – 300 mesh iron-based Fe–1% Sn–1 ½% Cu compacts, but had no influence when this mixture was based on –100 mesh iron powder, or when the mixture composition was Fe–2% Sn–3% Cu. The effects have been examined in relation to the sintering mechanism by scanning electron microscopy and by X-ray microanalysis.
Notes
* Manuscript received 16 June 1972. Contribution to a Symposium on ‘The Role of Surface Properties in Powder Metallurgy’ to be held in Eastbourne on 20 and 21 November, 1972.