US2212178A - Alloy suitable for use as bearing metals - Google Patents

Description

Patented Au 20, 1940 I i 2,212,178

UNITED STATES PATENT OFFICE Paul Kemp, Vienna, Germany No Drawing. Application July 21, 1938, Serial No. 220,562. Austria July 21, 1937 3 Claims. (Cl. 75-166) This invention relates to alloys suitable for As a result of these investigations it was found use as bearing metals. that alloys, which showed only slight difie'rences The suitability of alloys as bearing metals is in in e d g S e g and compressibility. general determined by investigation of a series easionally v e y eensiderabiy in their P of properties which have been recognised to be S OI St ength a d t a alloys a g a high 5 essential. Essential requirements are a sum- Percussion strength are best adapted r ciently high resistance to compression to ensure s pose to percussion p the alloys withstanding the occasionally high r n s carried ut y t a y w d surface pressures, a certain hardness, to ensure that in Order to Obtain Sliflieieht DereuSSiQh 0 suflicient resistance being offered to the squeezing Strength in alleys of the three Component System 10 out of the metal from the bearing, and also suffia nyn t antimony content oient upsetting and transverse strength which gether wi h a of the ts arsenic a d dserves as a standard for the tenacity of the alloy, m um advantageously ad i dening conthis last property being of very great importanc stituents, must not exceed the tin content and particularly in the casev of strong impact stresses. that the lead content must amount to at least 15 In addition thereto, the sliding properties, capai bility of being satisfactorily cast and economic on the other h it has in general been found c nsiderations play a corresponding part, to be advisable, in order to obtain as favourable In view of the foregoing, the established fact hardness and strength s possible, that h qu that alloys, which with regard to all the above iny 0f antimony in the alloy together With 20 dicated properties fulfil the conditions required quantity of the arsenic Cadmium Should of satisfactory bearing metals and hi 1 not be substantially less than the quantity of tin showed no appreciable differences from-one anpreseht- Aeel'itent of C p 1 t0 has no other, behave quite differently in operation, was influence 0n the Percussion Strength of these surprising; Aboveall it was observed that in alleys- The composition of these alloys P 25 bearings, which are exposed to impacts, some of tieuleily p d s hearing met st acthese alloys developed cracks and in part also cordihgly be maintained approximately W t crumbled out, whilst others completely withstood the feliewing limits:

the stresses.

. According to this invention, it has been found g g fgjg 94% 30 that an adequately high bending strength together with a certain compressibility are not arsenic plus sufficient indications of the suitability of an alloy cadmium 104,7 preferably 94% f whih for bearings exposed to impacts. In actual fact of whichAs=14 5% also in the investigation of these two properties of which the procedures taking place inpractical operation are only very incompletely represented, since, If desired, up to 2%, preferably only up to 1.5% of whilst the impacts and percussions occur suddencopper in addition. ly in the bearing, the determination of the bend- Y a t the proportions of the components 40 ing strength and compressibility requiresaperiod n the above indicated limits, the hardness of 40 of a few minutes. the alloy can be extensively influenced. The i The working conditions are much better reprelower the content of tin and accordingly also the sented in the percussion test. There are no nt s f S AS a the lewet is the hardstandards for carrying out this test for bearing ness of e a y- I the ease of arsenic addition metals and, since it was only a question of comup to 1% and in the case of cadmium addition up 45 parative tests and not of the determination of to about 1.5% ar Suitable, but the 811!!! Of these absolute values, the applicants investigations two additional metals must not exceed 2%. since weretherefore carried out with an arbitrarily seno particular advantages are obtained thereby. V lected drop hammer, in such a way that'the latter Bearing metals of t Same y System h in 'was allowed to fall from the same height and at a low content of copper have already been pro 50 equal intervals of time onto a rod supported at posed, p t y in the pp a t's Austrian two positions. The number of impacts required Patents Nos. 130,903 and 135,895 ant. U. S. A. for breaking the rod was taken as the value of Patent No. 1,754,364. The alloys 'according to the resistance to percussion or percussion these patents, however, differ considerably from Y strength. the alloys according to this invention in their 8% of Sn,10%- of Sb, 1.5% Of very much ;lower lead content, whilst on the other hand their content of antimony plus arsenic plus cadmium exceeds the upper limit according to this invention. I v A' comparison of .the six-component system alloy (1) indicated in Austrian Patent No. 130,-

.9 03 as optimum and having the composition: 10.4% of Sn, 9.8% 0f Sb, 1.45% Of C11, 1.5% Of,

Cd, 1.2% of As and 75.65% of Pb, with an alloy (11) according to the present invention, for e'xv ample: 9% of,Sn, 7% of Sb, 1.3% of Cu, 1% of Cd, 0.7% of As and 81% of Pb shows that the former under the same testing conditions breaks after three impacts whilst the latter only breaks alter 15 impacts. I with regard, to the resistance to compression andbending strength, no appreciable difierences exist between the two alloys, the latter alloy being merely somewhat softer This lower' hardness is however, not the cause of the higher per cussion strength," since for example alloy .(III), Cu, 0% of Cd, 1% of As and 78.5% 01 Pb, which possesses the same hardness as the above alloy (11)] likewise breaks after only three impacts.

It must be assumed that the better properties oi the all ys according to the present invention,

. are 0cc free lead in the texture. In alloys having a lower.

oned inter alla by small quantities of so lead content, lead cannot occur as a constituent \of the texture, since it is entirely used up for the iormation of the" ternary Pb-Sb-Sn-Eutectic.

Moreover, the known bearing metals of this system all contain a substantially higher quantity of antimony, 'which gives rise to the formation of more brittle crystals. The alloys according to the present invention are free from all the disadvantages of these known alloys. Moreover, owing to their higher lead content, they have the economic advantage of lower cost.

What I claim is: 1..A bearing alloy characterized by a high resistance to-impact stresses consisting of 80% to 86% of lead, 10% to 6% of tin, up to 2% 0t copper and 10% to 6% of antimony and at least one of the metals cadmium and arsenic, the amount of arsenic being at most-1%, the amount of cadmium beingat most 1.5%,.and the quantity of arsenic and cadmium together being at most 2%. Y

2. A hearing alloy characterized by a high resistance to impact stresses consisting of about 7,% to 9% of tin, 6% to 7% of antimony, 0.5% to 1.0% of arsenic,- 0.7% to 1.0% of cadmium, up to 1.5% of copper and the remainder lead.

3. A bearing alloy characterized by a' high resistance to impact stresses consisting of 81% 'of lead, 9% oi! tin, 7% of antimony, 0.7% of 1.3% of copper.

arsenic, 1% of cadmium and. i PAUL KEMP.