Numerical research on effect of overlap ratio on thermal-stress behaviors of the high-speed laser cladding coating

High-speed laser cladding technology, a kind of surface technology to improve the wear-resistance and corrosion-resistance of mechanical parts, has the characterizations of fast scan speed, high powder utilization rate, and high cladding efficiency. However, its thermal-stress evolution process is very complex, which has a great influence on the residual stress and deformation. In the paper, the numerical models for the high-speed laser cladding coatings with overlap ratios of 10%,30%, and 50% are developed to investigate the influence rules of overlap ratio on the thermal-stress evolution, as well as the residual stresses and deformations. Results show that the heat accumulation can reheat and preheat the adjacent track coating and substrate, resulting in stress release of the previous track coating and decreased longitudinal stress peak of the next track coating. With the overlap ratio increasing, the heat accumulation and the corresponding maximum residual stress position tend to locate in the center of the cladding coating, where the coating has a high crack susceptibility. For a small overlap ratio of 10%, there are abrupt stress changes from tensile stress to compressive stress at the lap joint, due to insufficient input energy in the position. Increasing the overlap ratio can alleviate the abrupt stress change and reduce the residual deformation but increase the average residual stress and enlarge the hardening depth. This study reveals the mechanism of thermal-stress evolution, and provides a theoretical basis for improving the coating quality.

Fabrication and performance evaluation of dissimilar magnesium-aluminium alloy multi-seam friction stir clad joints

This investigation is aimed to establish empirical relationships between continuous multi-seam friction stir cladding process parameters （i.e., rotational speed, welding speed and shoulder overlap ratio） and the quality characteristics （bond tensile strength, shear strength and corrosion） of dissimilar magnesiurn-aluminium alloy clad joints. The influence of considered process parameters on the clad properties was reported. Furthermore, multi-criterion optimization procedure was used to obtain ideal processing conditions, which can yield higher interface strength and lower corrosion rate of fabricated composite plate. Results indicate that, the aluminium-rich thin continuous layer, Mg-rich irregular shaped regions consists of A13Mg2 and Al12Mg17 interraetallic compounds and nature of mechanical interlocking has great influence on the joint interface strength. On the other hand, the corrosion resistance of the clad joints is greatly affected by the amount of magnesium mixed with top aluminium sheet during friction stirring. Also, bend testing shows that, the cladded joints exhibit excellent ductility.

Overlap maximum matching ratio （OMMR）： a new measure to evaluate overlaps of essential modules

Protein complexes are the basic units of macro-molecular organizations and help us to understand the cell's mechanism.The development of the yeast two-hybrid,tandem affinity purification,and mass spectrometry high-throughput proteomic techniques supplies a large amount of protein-protein interaction data,which make it possible to predict overlapping complexes through computational methods.Research shows that overlapping complexes can contribute to identifying essential proteins,which are necessary for the organism to survive and reproduce,and for life's activities.Scholars pay more attention to the evaluation of protein complexes.However,few of them focus on predicted overlaps.In this paper,an evaluation criterion called overlap maximum matching ratio(OMMR) is proposed to analyze the similarity between the identified overlaps and the benchmark overlap modules.Comparison of essential proteins and gene ontology(GO) analysis are also used to assess the quality of overlaps.We perform a comprehensive comparison of serveral overlapping complexes prediction approaches,using three yeast protein-protein interaction(PPI) networks.We focus on the analysis of overlaps identified by these algorithms.Experimental results indicate the important of overlaps and reveal the relationship between overlaps and identification of essential proteins.

Comparative study of big data of global adakites and mineralization-related granite in the Geza arc metallogenic belt, northwest Yunnan, Southwest China

The Geza arc is an important part of the Sanjiang tectono-magmatic belt and is a newly discovered copper polymetallic ore concentration area in northwest Yunnan province,Southwest China.The area comprises numerous metal ore deposits,including one super-largedeposit,three large deposits,etc.The formation of these deposits was closely related to intermediate–acidic magmatic intrusions.Based on previous studies,the“big data”analysis technique was used for a comparative study of large geochemical datasets of granite related to ore-formation in the Geza porphyry copper deposit and global adakites.As a result,1313 element combinations and 127,765 overlap ratios were obtained.The results show that the Geza porphyry has similar geochemical characteristics to global adakites(the ratios of REE and Ga to major elements are in the range of global adakites).However,theCu,Mo,and Zn contents of the porphyry are significantly higher than those of global adakites,and the porphyry may,therefore,represent an end-member of the global range of adakite composition.In addition,the geochemistry of adakites associated with the porphyry copper deposits overlaps in part with that of global adakites,although most of the data lie outside of the range of global adakites(i.e.lowMn/Cu,Sr/Cu,Na/Cu,and Zr/Cu values,and high Th/Cu,Ba/Cu,Na/Mo,Rb/Mo,Th/Mo,Ta/Mo,Ba/Mo,Mn/Zn,and Ba/Znvalues).The samples with characteristics that deviate significantly from the geochemistry of global adakites show more advanced mineralization and alteration,and a stronger relationship with Cu and Momineralization.The results of geochemical data mining can be used as a prospecting indicator,and provide a new scientific basis for geological prospecting of the deep levels and per-iphery of the Geza Cu polymetallic ore belt.