Preparation process of lossless pure platinum bar by using reducing-diameter die forging and lossless pure platinum bar

Abstract

A non-destructive pure platinum bar preparation process using diameter reduction die forging and the resulting pure platinum bars are disclosed. The process includes: high-frequency melting of platinum raw materials under inert gas protection to obtain pure platinum molten liquid; injecting the pure platinum molten liquid into a casting mold preheated to above 500°C to obtain a pure platinum cast rod; preheating the pure platinum cast rod and then hot-forging it using a step-by-step diameter reduction die forging method to obtain pure platinum bar stock, wherein the step-by-step diameter reduction die forging method includes at least three stages of die forging; repeatedly cold-rolling the pure platinum bar stock to obtain cold-rolled bars, with a total cold-rolling deformation of over 80%; and drawing the cold-rolled bars in multiple passes to obtain pure platinum bars with a diameter of 0.2~0.8mm. This invention's preparation process eliminates the need for machining to remove surface defects or adding reinforcing agents. Through the coordinated operation of process steps and parameters such as preheating the casting mold, step-by-step diameter reduction die forging, and cold rolling and drawing for strengthening, it ensures the complete elimination of surface defects and avoids the performance degradation caused by prolonged high-temperature heating in traditional processes.

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