Lists
Lists
Pearce, Sidney Cecil (1959) The effect of arsenic on tin-lead and lead rich lead-tin-antimony alloys. Doctoral thesis, Sir John Cass College.
Arsenic-tin-lead alloys containing up to 20% arsenic have been investigated by means of thermal analysis and micro-examination. A ternary eutectic was found in the vicinity of the lead-arsenic eutectic point. A further invariant point at the composition 1.48% Sn, 0.61% As, balance Pb, was found to be the eutectic point of a pseudo binary system of lead and the compound Sn3 As2. A liquidus surface diagram has been constructed for the ternary system.
The manner in which arsenic affects tin-lead solders was investigated by means of spreading-drop tests. A graphical relationship was obtained between the arsenic content and the advancing contact angle of a solder drop, representing the wetting power or "solderability".
Certain quaternary alloys of arsenic, tin, antimony and lead were investigated by thermal analysis and micro-examination, and a possible mode of solidification suggested. Crystals of the tin-arsenic compound Sn3As2 were present in most alloys, which in certain circumstances adopted a curved form. The mechanism of curvature was studied and possible reasons discussed.
The effect of varying amounts of arsenic on the tensile properties of tin-antimony-lead alloys was studied with the Hounsfield Tensometer. At elevated temperatures (100°C) alloys containing arsenic were found to retain their tensile strength to a greater extent than arsenic-free alloys.
Hardness tests were carried out at 20°C and 100°C and it was again found that alloys containing arsenic retained their hardness to a greater extent at 100°C. Certain ageing characteristics were found and hardness - time curves for all alloys investigated have been constructed.
Tests were made to compare resistance to wear of certain alloys, and optimum results were found with alloys containing 1% to 2% arsenic.
 |
View Item |