The Study Of Hot Working Die Repaired And Strengthened By Laser Biomimetic Coupling Technology

Mold industry is the basic industry of the national economy, are called "neverdecline of industry","Golden Touch" in the industry, in the automotive, electronics,instrumentation, motors, appliances and other communications products, there areabout2/3through the mold parts are molded. Because the mold with high precision,low consumption, high consistency, high efficiency and high complexity and othercharacteristics, so other domestic processing methods can compare to being a greatconcern at home and abroad. As we all know, hot die mainly depends on its surfacefor processing production, according to statistics80%of the hot work die failure isderived from its surface, and thermal fatigue is the main reason that led to this failure,so companies want to use a simple and effective way to deal with this a problem.In nature, can be found in the body surface of animals and plants have excellentversatility structure, which is the experience of millions of years of evolution of theresults, and these advantages are unmatched by traditional artificial materials. As weall know, when long-distance flying dragonfly, its wings can withstand airflow friction,under tremendous lift effect, showing excellent performance, the study found thiscontext with dragonfly wings reticular structure distribution. Plant leaves can be verygood to resist the invasion of wind, frost and snow without cracking, which showed anetwork-like and leaf-like structures parallel distribution. Many scientists discoveredthese advantages is biological in nature, and starting to focus on their research, recentresearch results appear gradually, where the application of bionic engineeringprinciples to solve some of the problems, and get unexpected results.Plant leaves and dragonfly wings and other organisms and has excellentresistance to fatigue crack stop function. They observed that the structure is acoupling structure, namely the distribution of different forms of hard on soft parent unit, alternating between each other. Through the analysis of these biologicalstructures, simplify and imitation, to design a die crack repair and strengthening ofbionic coupling model suitable hot. The purpose of this paper is to laser repairtechnology and bionic coupling theory, be used for the repair and strengtheningthermal fatigue cracks and crack the mold, to improve its thermal fatigue resistance,improve die life. In H13steel for the study, analyzed the bionic coupling fused endedcrack unit body repair individual characteristics, the effect of cell shape, spacing andsize of the sample after the repair of thermal fatigue resistance; repair of laser weldingmold bionic coupling weld reinforcement after cracking problem was investigatedafter the tensile strength and thermal fatigue performance enhanced sample. Theresults showed that:1.Repair and crack arrest based on biomimetic model coupling structure of plantleaves and dragonfly wings, made suitable for hot crack repair and strengthen themold. After generating a small thermal fatigue crack specimens bionic coupling fusedrepair, thermal fatigue resistance of each sample has been improved to varyingdegrees. Large cracks bionic coupling laser welding repair after strengthening toimprove the strength of the sample, thereby increasing its thermal fatigue resistance.2.Preparation of the repair on the different shapes of the fatigue crack arrest H13steelsubstrate bionic unit body, the base body to achieve restoration and strengthening ofmicrocracks. Unit composed mainly of martensite and austenite, with good toughness.After the crack to the unit body is blocked, the deflection occurs often or evenstagnation.3.Shape, size and distribution of the spacing unit have different effects on the body torepair the sample thermal fatigue resistance. Grid-like unit body surface samples foroptimal thermal fatigue resistance, spacing smaller, larger unit body blocking effecton the thermal fatigue crack is more obvious.4.Large size laser welding crack after repair weld heat affected zone is thermal fatiguecrack initiation and propagation of sensitive areas. Bionic coupling laser enhancedtreatment can significantly improve the tensile strength of the weld repair and thermalfatigue resistance. Distributed in the surface of the weld reinforcement unit body can resist the far-field tensile stress delay weld cracking, while preventing crackpropagation. The smaller unit cell spacing, the greater the intensity of the sample andthe thermal fatigue resistance increase rate.