The latest development of different preparation technologies of YAG∶Ce3＋ yellow phosphor used in white LED is summarized.These technologies include solid reaction method,sol-gel method,spray method,flash combustion method,coprecipitation method,coprecipitation-molten salt method and so on.Their advantages and disadvantages are compared,and their development trends are also pointed out.

Y2O3∶Eu3＋ red phosphor was prepared by microwave radiation,and orthogonal experiments were carried out to determine the optimal technological conditions,where heating rate is 20 ℃/min,calcination temperature 1 240 ℃,and holding time 60 min.The sample prepared under the above conditions is of 107.0% relative brightness.The phase structure,granularity and spectra of the sample were analyzed,and the results show that the sample is composed of a single pure phase of Y2O3,and it has uniform particle size of D50=3.28 μm.The maximum peak in the emission spectrum of the sample locate at 607 nm,and the color coordinates of the sample are x=0.653 3、y=0.342 4.

The latest development of LaFe-based room temperature magnetic refrigerant materials is introduced in respect of their magnetocaloric effects and preparation technologies.It is indicated that NaZn13-tpye LaFe-based compound with high Fe content is an excellent soft magnetic material,and its Curie temperature can be improved by substituting Co for Fe and adding some nonmetal elements such as H,C and B.When LaFe-based compound is prepared by melt spinning and adding other lanthanon to replace La,its annealed time can be shortened to form NaZn13structure.The LaFe-based compound with an appropriate element ratio may be a room temperature magnetic refrigerant material with giant magnetocaloric effect.

The two ingots were prepared by sheet double-sided cooling and plate single-sided cooling,respectively in the process of preparing Nd14.9Fe77.8Al0.3Cu0.2B6.8 magnetic material.Their microstructures and phase characteristics were analyzed,and their corresponding magnet samples were investigated on microstructure and magnetic property.The results show that the ingot prepared by sheet double-sided cooling is of more uniform grain size and less α-Fe phase than the ingot prepared by plate single-sided cooling.The magnet sample from the former ingot is of more homogeneous structure with 0.02 T higher residual magnetic flux density（Br）,2.5 kA/m higher intrinsic coercivity（Hcj）,and 2.8 kJ/m3 higher maximum energy product than the magnet sample from the latter ingot.

Based on the characteristics of cemented carbides,the development trends are described of the two series cemented carbides respectively applied in cutting tools and mining tools.And the emphasis is put on the comparison and analysis of high-performance cemented carbides and the preparation techniques of the powders prepared with special raw materials.

The manufacturing technologies,product characteristics,application and types of cemented carbides are briefly introduced.The development history of cemented carbide industry in China is reviewed,and its existing problems and shortages are analyzed.The development trend of new cemented carbide material is pointed out,and some advices about the future development of cemented carbide industry in China are presented.

The latest development of WC preparation technologies both at home and abroad is reviewed including solid phase method,fluid phase method,gas phase method and so on.Their advantages,shortcomings and possible ways to overcome are analyzed.The development trend of preparation research of nano is advised in china.

Adding nano-Al2O3 into WC-Co substrate may be useful to enhance the performance of cemented carbides.Based on the above view,the mechanical properties,wear and shock resistance,and microstructure of the composite material of nano-Al2O3/cemented carbide with different formula were investigated.The results show that adding proper nano-Al2O3 not only refines alloy grains,and improves microstructure uniformity and wear resistance of the composite material,but also enhances the strength of WC grain boundary,which plays a role of strengthening and toughening and results in fracture form shift from intergranular fracture to transgranular fracture of the composite material.Meanwhile,adding rare earth also improves the comprehensive performance of the composite material.Drill teeth made with the nano-composite materials are assembled into a drill bit that is then tested in situ.Compared with the drill bit assembled with cemented carbide drill teeth,the above drill bit is of 20% higher rock breaking efficiency and 80% longer service life.

Cemented carbide materials with different Co content were prepared by powder metallurgy,mechanical properties of the materials were tested at room temperature,and phase composition,microstructure and morphology were studied using XRD,SEM and so on.The results show that with Co content increasing,the binder phase（Co） in the microstructure is of an increased average free path（λγ）,the adjacency degree（C） of WC grains decreases,the bend strength of the material increases but hardness decreases.

四川航空工业川西机器有限责任公司（原名四川航空工业川西机器厂）始建于1965年。隶属于中国航空工业集团公司，是集科研、制造、服务于一体的国有大型二类企业。