Page 249 - The Tribology Handbook

B18 Cylinders and liners

MATERIALS AND DESIGN
Table 18.1 Choice of materials for cylinders and cylinder liners

Material
Commenf Surjacejnish and treatment
Block Liner
I.C. Monobloc Most petrol engines. Grey C.1. (low - Simplest and cheapest Most applications use an
engines Some oil engines phosphorus) method of building untreated cross-hatched
(‘siamesed’ mass-production honed finish-See Note 3
cylinders used for engines
cheaper and low
specific power Aluminium - Gives maximum reduc- For greater scuff resistance of
engines or where alloy (high tion in weight but C.I. a phosphate treatment
space is at a silicon) poses special problems can be used. For greater
premium) Aluminium with in material compati- wear resistance bores may be
nickel plate bility with mating hardened on surface,
containing component, i.e. through- or zone-hardened,
silicon piston and rings or hard chromium-plated on
carbide particles cast iron or steel liner. Sur-
face porosity (by reverse
Dry liner Oil engines and Grey C.I. (low Grey C.I. (low-to- Liner normally pressed- plating) is necessary with
petrol engines phosphorus) medium phos- in but may be slip fit. chromium Plating to give
phorus) Much improved wear, scuff resistance. Porous coat-
can pose cooling pro- ings aid oil retention reduc-
blems. Used for engine ing scuffing and wear. sili-
reconditioning in con carbide impregnation
monobloc system can be used to combat bore
polishing.
Aluminium Grey C.I. (low-to- Liner normally cast-in or Aluminium alloys (high silicon)
alloy medium phos- pressed-in require special surface finish
phorus) to allow free silicon to stand
out from the matrix. Nickel
Wet liner High-performance Grey C.I. Grey ‘2.1. (low-to- Wet liner requirement for plate with silicon carbide
petrol and most oil medium phos- long life, good cooling particles is the most common
engines phorus) Grey and ease of mainte- solution for aluminium
C.I. with silicon nance bores. Some cheaper alumi-
carbide nium alloys may be used for
impregnation ‘throw-away’ engines. Piston
Austenitic cast skirts may be electroplated
iron with iron or chromium.
Aluminium Grey C.I. High-performance
alloy austenitic C.I. petrol engines to reduce Costs rise significantly from the
Aluminium weight basic monobloc cast-iron cy-
alloy (high linder block. Care must be
silicon) taken to ensure the mini-
Aluminium with mum specification consistent
nickel plate with technical requirements
containing
silicon carbide
particles
Com- Monobloc Small size and low Grey C.I. (low - As in i.c. engines As in i.c. engines except where
pressors pressure (up to phosphorus) plastics piston rings are used
34 in dia. and in which case honed ‘mirror-
100 psi) finish’ is desirable
Wet liner Heavy duty long life As in i.c. engines As in i.c. engines
high reliability units
of all sizes and ope-
rating pressures
Hydraulic To suit - Grey cast iron Material depends on en- Fine turned or honed to mirror
actuators design Bronze vironmental require- finish
and fluid require- Aluminium ments of pressure,
piston ments alloy duty, reliability and Hardened steel bores usually
Pumps Steel fluid in use ground or lapped

B18.1