SU873024A1 - Method of checking uranium dioxide powder compact density - Google Patents

Description

(54) METHOD FOR CONTROLLING THE DENSITY OF THE PRESSING FROM URANIUM DIOXIDE POWDERS

one

The invention relates to powder metallurgy and can be used to control the density of compacts of powders such as uranium dioxide.

A known method of controlling the density of compacts from powder, based on the weighting of a known volume of powder 1.

However, this method is time consuming and time consuming.

There is also known a method for controlling the density, according to the dependence of the electrical resistivity on the applied pressure and, consequently, the density of the compacts from the powders, which consists in applying a constant voltage and measuring the electrical resistance of the compacting of the powder using a micro-meter 2.

However, this method allows only the average density of the entire compact to be determined, although it is often necessary to control the expansion. density determination by pressing height, which may be uneven.

The purpose of the invention is to control the uniformity of the density distribution in a given direction in the compact from uranium dioxide powder.

The goal is achieved by the method of controlling the density of a compact of uranium dioxide powders, consisting in applying an electrical voltage to a compact, to measure the electrical parameters of the compact at two polarities of the applied voltage and determine the uniformity of the density distribution values of electrical parameters of the same name, as electrical parameters measured at two polarity values of the applied electrical voltage, zuyut voltage and current to the scoop.

The essence of the method is to measure. The rhenium of the electrophysical characteristics of the compact after the steady-state current transfer is established and consists of the following operations: filling the powder in two. uranium oxide in a sleeve of non-conductive material, the introduction from the ends of the sleeve 20 electrodes of punches and one-sided pressing at a pressure of 5-10 Pa, the connection of electrodes to a source of constant voltage via ballast resistance and

measuring the voltage drop across the resulting compact and the current through it, applying a voltage of opposite polarity, and measuring the magnitude of the voltage drop across the pressing and current through it. The magnitude of the voltage drop and the current through the compact need to be measured some time after the establishment of the stationary mode (10 s).

Using the proposed method makes it possible to control the uniformity of density distribution during pressing, in particular uranium dioxide tablets, to obtain high-quality products without distorting their shape during sintering.

Claims (2)

1. A method for controlling the density of a compact of uranium dioxide powder, consisting in applying an electrical voltage to the compact, characterized in that monitoring the uniformity of the density distribution in a given direction in a compact of uranium dioxide powder, measuring the electrical parameters of the compact at two polarities of the applied electrical voltage and determining the uniformity of the density distribution from the resulting difference in the electric parameters of the same name. 2. The method according to claim 1, characterized in that the voltage and current in the compact are used as electrical parameters measured at two polarity values of the applied electrical voltage. Information sources,, taken into account in the examination 1. USSR author's certificate number 569895, cl. G 01 N 9/00, 1975. 2. Radomysylsky, I.D., et al. Compaction and electrical resistance of metal powders and their mixtures at low cold-pressing pressures. “Poroshkov Metallurgists, No. 1, 1976, p. 8-12 (prototype).