有色金属铸造培训材料.pptVIP

Non-Ferrous Casting Alloys Introduction Aluminum Alloys The Al-Si System Microstructural Modification Degassing Heat Treatment Specifications, Properties, Applications Magnesium Alloys Specifications, Properties, Applications Non-Ferrous Casting Alloys Literally any casting alloy not iron-based Aluminum Magnesium Zinc Copper its alloys (brass/bronze) Titanium Cobalt Non-Ferrous Castings Brief History ~3000 BC – First cast objects (copper) 1775 AD – N-F foundryman Paul Revere rides Boston - Lexington 1849 – Manually operated die casting machining patented (lead) 1876 – First aluminum casting – an engineer’s transit – chemically produced Al is $1/oz. 1884 – Cast Al pyramid mounted on tip of Washington Monument 1886 – Electrolytic Al reduction process discovered – Al goes from $15/lb. To $0.50/lb. 1903 – Wright Flyer uses a cast Al block and crankcase (152 lb.) 1907 – Discovery of enhanced cast Al properties through heat treatment Non-Ferrous Castings Brief History 1921 – Modification of Si structure in cast Al discovered 1928 – Alcoa develops Al vehicle wheel for truck trailers mid-1950’s – Squeeze casting developed in Russia 1958 – Full Mold (aka Lost Foam) process patented 1969 – Chevy Vega introduced – 1st cast Al block with parent-metal cylinder bores 1981 – GM begins production of Al cylinder heads by Lost Foam process – Saturn makes all blocks, heads, cranks and diff cases in 1985 1988 – Ford adopts Cosworth process for high volume production 1994 – Dephi produces first squeeze cast chassis components Aluminum Aluminum - Negatives Pure aluminum is uneconomical and has undesirable properties Electrolytic reduction from bauxite ore is difficult and expensive Washington Monument Very soft and weak Aluminum - Positives Pure aluminum has many desirable properties Good conductivity Very resistant to uniform corrosion Good strength-weight ratio Recycling of aluminum is cost-effective due to a low melting point Aluminum How do we “harness the possibilities” of aluminum