基于R语言的陶瓷样本化学成分数据可视化分析

随着大数据时代不断发展,数据中蕴藏着丰富的知识,且其价值日益提升。为了更好地认识数据规律,通过从UCI数据库中选取陶瓷样本化学成分数据集,基于开源的R语言对该数据集进行了预处理,然后使用不同的功能函数进行可视化与分析,经过实验探索在一定程度上反映了陶瓷样本数据中化学成分的规律。

TiC基金属陶瓷配方的正交试验研究

通过正交试验法对TiC基金属陶瓷进行成分研究,选取抗弯强度为试验指标,进行极差分析,获得了最佳的TiC-WC-Cr3C2-Co-Ni-Mo金属陶瓷试验配方A2B3C1组合。试验表明Mo含量的增加使环形相增厚;Mo含量和Co/Ni含量比为抗弯强度的两个主要成分影响因素。

陶瓷合金浸蚀特性的研究

为了研究不同成分、组织及性能的陶瓷合金的耐浸蚀磨损性能,采用了0.1～0.3mm碳化硅和二氧化硅磨粒浸蚀剂,撞击角度为30°～90°,撞击速度为30～80m/s,对8种陶瓷合金靶材试样进行了浸蚀试验。此外,还用多普勒风速计测量技术来研究固体磨粒浸蚀剂对陶瓷靶材试样相互作用的过程,系统研究了撞击变量变化对撞击过程的影响。

陶瓷合金浸蚀特性的研究(续)

为了研究不同成分、组织及性能的陶瓷合金的耐浸蚀磨损性能,采用了0.1～0.3mm碳化硅和二氧化硅磨粒浸蚀剂,撞击角度为30°～90°,撞击速度为30～80 m/s,对8种陶瓷合金靶材试样进行了浸蚀试验.此外,还用多普勒风速计测量技术来研究固体磨粒浸蚀剂对陶瓷靶材试样相互作用的过程,系统研究了撞击变量变化对撞击过程的影响.

刚玉

Ceramic components built by stereolithography,Ceramic on ceramic bearings in total hip arthroplasty, Characterization of particle orientation in tape cast alumina green body using a polarizing microscopy, Colloidal processing of aluminum oxide powder for membrane applications,Comparison of interfacial chemistry at Cu/a -alumina and Cu/γ -alumina interfaces,Comparison of the wear properties of polyethylene plate in total knee prostheses (TKP) using different femoral component materials.

Synthesis and ceramization of polycarbosilane containing beryllium

Polycarbosilane containing beryllium(BPCS) precursors was prepared by the reaction of polycarbosilane(PCS) with beryllium acetylacetone(Be(acac)2).The analysis of structures and components of BPCS demonstrates that their main structures are basically the same as PCS.Ceramization of BPCS precursors shows that BPCS precursors are organic below 600 °C and inorganic at 800 °C.At 1400 °C,BPCS precursors convert into silicon carbide ceramics.The ceramization of different beryllium content precursors were studied,which show that beryllium plays an important role in the inhibition of crystalline grain growth of β-SiC at high temperature and it can adjust the dielectric constant of silicon carbide ceramics.

Preparation and characterization of a composite membrane based on the asphaltene component of coal

Asphaltene-ceramic composite membranes were fabricated from ceramic supports and an asphaltene component, which was obtained from the separation of coal to give a kind of new carbonaceous precursor material. Using SEM and thermogravimetric analysis to measure the microstructure and properties of the asphaltene component allowed the porosity, permeability, and retention ratios to be determined. The results show that the asphaltene component can be regarded as a good carbon membrane precursor material because of its high carbon content and strong bonding capacity. When ceramic supports are impregnated with asphaltene colloid the asphaltene easily combines with the support surface and forms a good carbonaceous film after carbonization. Little of the asphaltene component permeates into the internal pores of the ceramic support. Although the number of coats applied to the substrate had little affect on the porosity of the asphaltene-ceramic composite membranes the permeability varied depend- ing upon the number of times the substrate was treated. The way bubbles escape from the film, and the phenomenon of coalescence, as affected by different film thicknesses also seem closely related to the number of coats. A composite membrane carbonized at a final temperature of 600℃ is relatively dense and the permeability of Fe（OH）3 colloid through it is very low. A membrane fired at 800℃ is porous and its permeability and retention of Fe（OH）3 colloid are 88 L/（m2 h MPa） and 85.3%, respectively when the trans-membrane pressure is 0.22 MPa.

Study of the Firing Temperature of Marajoara Archaeological Ceramics by EPR Associated to INAA Data

The Marajó Island is the largest island of the Marajō archipelago, located in the north of Brazil. In this region, at the end of 19th century, it was identified an archaeological society named Marajora, which occupied the island from 400 to 1,350 AD. It was characterized by a ceramic style recognized by its beauty and exuberance. Until this moment, the physical and chemical analysis studies in this ceramics are scarce and this kind of studies may help archaeological studies performed in the island. With this purpose, this work presents a preliminary study of the firing temperature in the ceramics. For that, the elementary concentrations of 109 samples from Museu de Archaeology and Ethnology Museum of the University of Sáo Paulo and samples collected in the Marajá Island were studied. The samples were analyzed using instrumental neutron activation analysis in which the elemental concentration of Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sc, Sm, Ta, Tb, Th, U, Yb and Zn were determined. The interpretation of the results was made using multivariate statistical approaches and showed the existence of three chemical groups. Some samples of each cluster were chosen for the determination of their firing temperatures by electron paramagnetic resonance, in order to verify if different firing temperatures was associated with different elemental groups of ceramic samples. The results showed that there are no statistical differences in the firing temperature between the samples from Archaeology and Ethnology Museum and the contemporary samples of the Marajá Island.

Preparation of porous silicon carbide by combustion synthesis

Porous silicon carbide ceramics were prepared by combustion synthesis technique. SiC/TiC composite was gained by combustion reaction of Si, C and Ti. Thermodynamics analysis of Si-C-Ti system indicates that the content of TiC in products should be larger than 30%. The experimental results show that the content of Ti+C should be larger than 25% to achieve a complete combustion reaction. The X-ray diffractometry results show that the final products with a relative density of 45%64% are composed of α-SiC, β-SiC, TiC and a small quantity of Si. The images of scanning electron microscopy show that the structures of grain in SiC based porous ceramics consist of particles with a few microns in size.