Web Of Tech

Mixed Praseodymium and Neodymium Oxides As Catalyst For Synthesizing DOP, DOM and DOA

CHEN Qi-rui;ZHANG Feng-mei;LUO Ming-run;JIAO Zhao-lin

Rare Metals and Cemented Carbides | Vol., Issue 2, 1994 | pp. 1-4

The cheap raw material, mixed praseodymium and neodymiumoxides, can be used as catalyst for synthesizing plasticizer, such asDOP, DOM and DOA, with significant catalytic effect. The productscan be purified through simple processes. The catalysts can be recovered and regenerated with the same catalytic ability.

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Milling Behaviours of Various Ni Powders and Their Effects on the Structure and Properties of WC-9%Ni Cemented Carbide

ZHOU Jian-hua;SUN Bao-qi;WU Guo-long

Rare Metals and Cemented Carbides | Vol., Issue 2, 1994 | pp. 5-10

In this paper, the milling behaviours of carbonyl. electrolyticand reduced Ni powders and' reduced Co powder and their effects on thestructure and properties of WC-- 9 qoNi cemented' carbide are investigatedrespectiyely. The results show that Ni powder is much more aggregatedduring milling than Co powder. Of all Ni powders, carbonyl Ni powderhas the best technological performance. A new type of cemented carbide,equiyalent to WC--CO alloy, can be obtained from the carbonyl Nipowder and by process improvements.

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Change of Micrographs during Co Powder Production and Its Influence on Characters of WC--Co Mixture

ZOU Xu-mei

Rare Metals and Cemented Carbides | Vol., Issue 2, 1994 | pp. 10-16

A SEM study is made on Co oxalate, Co oxide and Co metalpowders obtained from above sources. Detailed micros tructure comparison shows the change of their micrographs. Technological propertiesof WC--Co mixtures made from both powders are not the same. Presentpaper giyes a description of their influence.

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Study of Hot Pressed Micro--crystalline Boron Carbide

ZHOU Rong-xing;WANG Ling-sen;DENG Ke-qin;YANG Ju-mei

Rare Metals and Cemented Carbides | Vol., Issue 2, 1994 | pp. 16-20

Study is made of hot pressing of micro--crys talline boron carbide from ultra--fine boron carbide. The grain size, porosity, transverse s trength, fracture morphology and I notion factor of the ma tenalis also investigated. The relationship between transverse strength andgrain size is expressed' as follows: a￣387. 6+ 182. 3 1The friction factor of boron carbide is determined as: K￣0. 093.

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Application of Aqueous Caustic Ball Milling To Wolframate Production

WEI Guang-jing;YU Nong-fang

Rare Metals and Cemented Carbides | Vol., Issue 2, 1994 | pp. 20-22

Practice shows, that the use of aqueous caustic ball milling ofwolframite concentrates instead' of traditional water ball milling notonly can reduce the mill liner wear and ball consumption, but also increase the decomposition rate during thermic caustic decomposition, a ndlower the consumption of flake caustic and operation cost. Thisprocess is practical and+' efficient.

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Development and Application of The New Synthetic Diamond Tip

LUO Xin-geng;WANG Xing-hua;LIU San-sheng

Rare Metals and Cemented Carbides | Vol., Issue 2, 1994 | pp. 23-25

The test and application of a new efficient and durable synthetic diamond tip on disc saw are described. The diamonffeimpregnatedtip features good' performance, long life and high efficiency. Its cuttingefficiency and tool life are increased by 25qO and' 48. sqO respectivelyas compared to other diamond tips when it is used for cutting 7--scalehard rock.

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