The principle of ion plating has been analyzed in this paper, And a noveltechnology for ion plating of imitation gold Cu-Al-in alloy on the surface of NdFeB permanentmagnetism alloy has been studied. The reasonable technical conditions for obtaining homogeneousbeautiful coating layer with tiny crystal particles were as follows: workpiece bias voltage: 200 V,main arc current: 5 A 2 0. 25 A, optimum workpiece height: 120 mm, evaporation heating power:11 kW, PAr: 1. 33 Pa～0. 0133 Pa, time: 30 min.

Tde particles in Al matrix were prepared successfully from powders of Ti, B andAl by means of SHS technique. The effect of aluminium content and the temperature of synthesison the SHS process, phase comPOsition and microstructure of the reaction products have beenstudied. The mechanism involved in the synthesis of TiB2 in Al matrix has been discussed. Theresults show that TiB2 particles may form in Al matrix at temperatures even about 800 t owingto the exothermic reaction between Ti and Al POwders. The presence of Al may hinder thereaction between Ti and B powders. The size of TiB2 particles is 5. 0 to 0. 5 pm, according to theAl content of the system.

The anvil materials for hot upset applications are reviewed in the present paper,and an emphasis is put on processing parameters, the compositions and key properties of the highTungsten alloys for anvil application. The resultS show that the alloys have high red hardness, i.e.198HV at 500℃ and 168HV at 800t for W232 alloys. Therefore, W253 and W232 alloys aresuitable for fabricating air exhaust valve, while W153 and W132 for air inlet valve. Tear lifespanis 10 ～ 30 times longer than that of Cu-W80, and the rate of finished products increases from58 % to 98 %.

For systematic analysis of the influence of RE on microstructure and physicalproperties of AlMg3W alloy, the metallographic inspections and X-ray diffractions have beenundertaken, and contrast tests have been made with respect to the mechanics property,wearability, welding property, thermal expansion property. The results show that AlMg3W alloywith 0. 05 % RE has the optimum property.

China's cemented carbide industry has witnessed big change from the traditionalplanned economy to the market economy. its over ten years of clevelopment has shown that theoutput of cemented carbide is closely related to steel output. Thus forecasting and study are madeon its market absorption capacity based on the development plan of the steel output. It is pointedout that since 1997, tile cemented carbides market has been improved, as will continue until2000.

Brief description is made of the properties, production, research and applicaations ofrefractory Ta & Nb and their alloys. It is indicated that Ta/Nb industry has a big progress withthe development of electronic industry and steel-making industry(The latest application anddevelopment of Ta/Nb in the other fields and China's production and application are also given inthe paper.

The paper describes Ta characteristics and mineral resources, and reviews itsapplcations and potential application in the fields of cemented Carbides, Chemital industry,aeronutics and aerospace, electronics, automobile, supesaloys, armorpiercers and medicahygiene.

Description is made of the present application and manufacturing method of therefractory metals comPOsites incl refractory metal matrix and compound matrix types, laminated,refractory metal fiber-reinforced type functional gradient materials, super-conducting etc) Thefuture development of refractory metal composites is forecasted.

In consideration of the fact that mechanical activation affects the surface fractal property of solid, the leaching kinetic equation was rededuced in the light of fractal geometry. This equation shows clearly the increase of surface fractal demention will accelarate the leaching. This effect was distinguished from that of the increase of k value due to mechanical activation and decrease of γ0 due to milling.

Investigation is made on the low-concentration, low-addition HCl digestion of scheelite concentrate. The results show that the average digestion rate can reach 97. 35% in 1. 5 hour at 95～10℃ with the addition of HCl (10% concentration ) .1. 5 times more than the theoretical value. Compared with the traditional acid digestion process, the said process can bring about large reduction of HCl consumption and concentration, resulting in large reduction of waste acid treatment cost and elimination of HCl gas volatization during acid digestion. In this way, the working conditions are improved and the cost for the control of HCl gas pollutant for environmental protection is also reduced. However, the said technology doesn't remove Mo and needs larger acid liquid volume (1. 5 times as much as that of the traditional technology).