A Study On Preparation Technology And Properties Of YG6Coarse Grain Cemented Carbide

Coarse particles cemented carbide materials are widely used in the production of cold heading die, mill roll, mining ball gear, shield machine heads. Extremely bad working conditions in these parts, thus demanding the performance of the material. In this study, funded by the National Natural Science Foundation, it is aims to study the traditional carbide production process to explore a suitable preparation of coarse-grained cemented carbide production process. This paper focuses on the influence of different C content of the alloy composition and performance; also studied the different milling time, sintering process, suppression of the sintered body microstructure and properties of WC-Co mixed materials; and alloys The fracture mode and fracture sources were discussed. Paper to complete the main work and research results are as follows:(1) Alloy samples are prepared by wet milling process using conventional carbide WC-6Co mixture. Studies have shown that a significant role in crushing milling of WC, but also conducive to the Co phase between the WC particles dispersed. Appropriate milling time, be able to maintain a mixture of WC particles, narrow particle size distribution, but also makes the Co-phase uniform distribution.(2) Alloy samples was prepared successfully by pressing and sintering. Studies have shown that the milling time can improve the alloy homogeneity and enhanced alloy mechanical properties, this study is the best milling time24h; hydrostatic compaction to improve green density, the alloy caused by increased density, reduce the residual porosity; low pressure sintering to eliminate cobalt alloy pool to promote the Co phase dispersed alloy mechanical properties.(3) A study on organization and the mechanical properties of alloy samples prepared by the six groups of different C content of the mixture. The results showed that the alloy specimens organizations must maintain a normal WC+γ two-phase region, in order to get a good hardness, flexural strength and impact toughness, decarburization, carburization comprehensive mechanical properties of the alloy adversely.(4) investigate the strengthening mechanism and fracture of the coarse-grained cemented carbide material source. Studies have shown that coarse-grained carbide fracture mode is mainly transgranular fracture, need to match the greater fracture energy; porosity, impurity elements and the abnormally large grains surrounding intergranular fracture, and easy to form the fracture of the alloy samples sources.