Lost foam casting process for casting with good mechanical properties

Abstract

The invention discloses a lost foam casting process for a casting with good mechanical properties. The lost foam casting process comprises the following steps of preparing all main parts from foam material blocks, and bonding all the prepared main parts to prepare a casting model; bonding a pouring gate for the casting model, and coating a refractory material at the outer sides of the casting model and the pouring gate to prepare a final model; placing the final model into a sand box, filling the sand box with dry sand, compacting by using a three-dimensional compacting table, and coating a plastic film on the sand box; uniformly introducing negative-pressure airflow to the sand box from top to bottom until the negative pressure is up to 0.04MPa below zero to 0.08MPa below zero, wherein the negative-pressure airflow is mixed gas of oxygen, nitrogen and carbon dioxide; and pouring molten metal into the region where the final model is arranged in the sand box, gasifying to enable the final model to disappear, replacing the final model with metal, and cooling to obtain the casting. By using the lost foam casting process, generated solid / liquid-phase products can be effectively reduced, molten metal can be prevented from being polluted, the heat radiating effect of metal becomes good, and the mechanical properties of the metal are improved.

Description

technical field [0001] The invention relates to a lost foam casting method, in particular to a lost foam casting process with good mechanical properties of castings. Background technique [0002] Lost foam casting (also known as solid casting) is made of foam plastic (EPS, STMMA or EPMMA) polymer material to form a solid mold with exactly the same structure and size as the part to be cast, after dipping refractory coating (strengthening , bright and clean, air-permeable) and dried, buried in dry quartz sand and subjected to three-dimensional vibration modeling, pouring molten metal into the casting mold sand box under negative pressure, so that the polymer material model is heated and gasified and drawn out, and then is cast Liquid metal replaces the one-time molding casting new technology formed after cooling and solidification to produce a new casting method for castings. [0003] However, during lost foam casting, due to the thermal effect of the molten metal during the ...

AI Technical Summary

Problems solved by technology

[0003] However, during lost foam casting, due to the thermal effect of the molten metal during the gasification of the model, a large amount of high-activity solid-liquid phase products will be generated near the molten metal and the newly formed casting, polluting the molten metal, causing carburization, hydrogenation, etc. Defects, and cause the heat dissipation effect of the molten metal to deteriorate, resulting in a decrease in the mechanical properties of the metal