Study On The Manufacture Technology And Technical Theory Of Bronze Powder

The development of packaging and mounting depends on quality of the bronze powder. Fuithennore, the bronze powder of high quality can only be produced by adopting the advanced equipment and technology h-i this paper, the theory of designing the equipment and the corresponding technology used for making bronze powders are first investigated in our countiy. The physical properties of the bronze powders made in China and those of imported ones are compared. The relationship between the hue of copper zinc alloys and alloying component as well as conditions of oxidation are analyzed. Through atomizing practices new kinds of atomizers are developed and main influence factors are studied. The technology of ball milling and its related theory are investigated. Research has been done in the methods of drying and bright anneals. The grading methods for bronze powders and the polishing methods were initially studied. The new high quality product is obtained by using these new equipment and technologies. More details are given as follows: 1. Comparison of the bronze powders made in china with imported ones concludes that the national bronze powders have some disadvantages, such as its cross-section looks like convex lens and the ratio of diameter to thickness is about 18, but the ratio of imported products with thin line cross-section is 80. The domestic particles with wide size distributions contain a large proportion of too small powders. The reasons for small covering power on water, high apparent densit~ small leafing value and low leafing speed are the unsatis1~抜ng shape of cross-section. The wide distributions of particle size and the large proportion of smaller powders have large impact on hue and metallic gloss. 2. The results of the relationship between the hue of copper zinc alloys and component as well as oxidation indicate that the alloying elements such as zinc, silicon, and nickel increase the yellow color degree of copper alloy, while aluminum decreases it; and that rare-earth cerium makes copper alloys become brighter; and that the property of anti-discolor of copper alloys is enhanced by adding the alloying elements such as zinc, aluminum, silicon and cerium; and that the yellow saturation of copper zinc alloys is enhanced by oxidizing copper zinc alloys at 1200C and more colors such as fire red, orange, blue, purple appear at 200扖. These results provide new tmins of thought for the hue of bronze powders research. 3. Four new atomizers have been developed, and one new type of them with ring holes, multiple focusing and 1800 tangential gas-entering has been first designed by introducing the idea of multiple-atomization in the single one. Production and experiments show that these four atomizers can meet the requirements of atomization of bronze powders, especially the atomizers with ring III holes, multiple focusing and 1800 tangential gas-entering have many advantages such as lower atomizing pressure, smaller powder mean size and easy control. The analysis of dynamics in atomization reveals that the mani reason of hole-congestion during atomization is that the negative pressure under the mouth rim is too large. And it is put forward firstly and also proven that the pressure gradient value should be smaller than or equal to that of density of atomizing material multiplied by acceleration of gmvi~ and under this condition copper zinc alloys can be atomized successfully. The optimum process of the atomizer with ring holes, multiple focusing and...