Agricultural machinery investment casting

1. oxidation slag inclusions

Measures to prevent oxidation weld tumor: strict control of the smelting process, rapid smelting, reduce oxidation, thorough slagging. Under the covering agent must melt aluminum and magnesium alloy. Furnace wall, tools should be cleaned, no oxidation, should be preheated, coating should be dry. The forging system must have stable flow, cache and slag skimming ability. The inclined pouring system is chosen to make the liquid flow smoothly without secondary oxidation. The selected coating has strong adhesion and produces slag in investment casting technology castings without shedding.

2.Cracking

Measures to avoid thermal cracking: prevent partial overheating and reduce the thermal stress in the specific pouring system. Must ensure the above 5 moulds and key berm °,Inverted riser can be extracted after condensing core molding, sand core can replace the metal key if necessary. Control the thickness of the plating to ensure consistent cooling rate of the investment mold precision casting furnace bar castings. Select the appropriate mold temperature, according to the thickness of the casting. Optimize the alloy organization to improve the thermal cracking ability. Improve the structure of the casting to remove sharp corners and thickness abruptness to reduce the tendency of thermal cracking.