“三创五育”背景下“双一流”高校本科人才培养的DIE模式初探及评价

针对新时代背景下“双一流”高校人才培养的发展需求,在“三创五育”理念指导下,解析基于产学研合作理论引入的DIE模式的内涵,系统阐述了DIE理念贯彻下的教学系统设计并付诸实践,旨在打破教学系、研究所、企业之间的壁垒,为学生学习、实践提供更多样化的渠道。问卷调查结果表明DIE模式在本科生团队协作、学术创造、自信心树立等方面有切实作用,为培养全面发展的高素质本科人才提供了参考。

Thin-walled and large-sized magnesium alloy die castings for passenger car cockpit:Application,materials,and manufacture

In order to effectively reduce energy consumption and increase range mile,new energy vehicles represented by Tesla have greatly aroused the application of integrated magnesium(Mg)alloy die casting technology in automobiles.Previously,the application of Mg alloys in automobiles,especially in automotive cockpit components,is quite extensive,while it has almost disappeared for a period of time due to its relatively high cost,causing a certain degree of information loss in the application technology of Mg alloy parts in automobiles.The rapid development of automotive technology has led to a higher requirement for the automotive components compared with those traditional one.Therefore,whatever the components themselves,or the Mg alloy materials and die casting process have to face an increasing challenge,needing to be upgraded.In addition,owing to its high integration characteristics,the application of Mg alloy die casting technology in large-sized and thin-walled automotive parts has inherent advantages and needs to be expanded urgently.Indeed,it necessitates exploring advance Mg alloys and new product structures and optimizing die casting processes.This article summarizes and analyzes the development status of thin-walled and large-sized die casting Mg alloy parts in passenger car cockpit and corresponding material selection methods,die casting processes as well as mold design techniques.Furthermore,this work will aid researchers in establishing a comprehensive understanding of the manufacture of thin-walled and large-sized die casting Mg alloy parts in automobile cockpit.It will also assist them in developing new Mg alloys with improved comprehensive performance and new processes to meet the high requirements for die casting automotive components.

Compression properties of cost-efficient porous expanded clay reinforced AA7075 syntactic foams fabricated by industrial-oriented die casting technology

In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and anti-pollution.At this point,aluminum syntactic foams(ASFs)are new-generation engineering composites and come into the upfront as a problem-solver.Owing to their features like low density,sufficient elongation,and perfect energy absorption ability,these advanced foams have been considerably seductive for many industrial sectors nowadays.In this study,an industrial-oriented automatic die casting technology was used for the first time to manufacture the combination of AA7075/porous expanded clay(PEC).Micro evaluations(optical and FESEM)reveal that there is a homogenous particle distribution in the foam samples,and inspections are compatible with the other ASF studies.Additionally,T6 aging heat treatment was operated on one half of the produced foams to explore the probable impact of aging on the compressive responses.Attained results show that PEC particles can be an alternative to expensive hollow spheres used in the previous works.Besides,a favorable relationship is ascertained between the aging treatment and mechanical properties such as compression strength and plateau strength.

Effect of slow shot speed on externally solidified crystal,porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy

The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg alloy.The AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg alloy.Refining elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-Al.At a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and net-shrinkage.With an increase in slow shot speed,the size and number of ESCs and porosities significantly reduce.In addition,the distribution of ESCs is more dispersed and the net-shrinkage disappears.The tensile property is greatly improved by adopting a higher slow shot speed.The ultimate tensile strength is enhanced from 260.31 MPa to 290.31 MPa(increased by 11.52%),and the elongation is enhanced from 3.72%to 6.34%(increased by 70.52%).

Characteristics and distribution of microstructures in high pressure die cast alloys with X-ray microtomography:A review

Al and Mg alloy high pressure die castings(HPDC)are increasingly used in automotive industries.The microstructures in the castings have decisive effect on the casting mechanical properties,in which the microstructure characteristics are fundamental for the investigation of the microstructure-property relation.During the past decade,the microstructure characteristics of HPDC Al and Mg alloys,especially micro-pores andα-Fe,have been investigated from two-dimensional(2D)to threedimensional with X-ray micro-computed tomography(μ-CT).This paper provides an overview of the current understanding regarding the 3D characteristics and formation mechanisms of microstructures in HPDC alloys,their spatial distributions,and the impact on mechanical properties.Additionally,it outlines future research directions for the formation and control of heterogeneous microstructures in HPDC alloys.

语义构建中的认知识解因素——以die of X和die from X为个案

语义构建离不开认知识解因素。die of和die from可以与同样的表达式搭配,即die of X和die from X。就规约意义而言,die of X通常表达客观的、直接的原因,而die from X通常表达客观的、间接的原因。但在die of X和die from X语义构建过程中,通过认知识解,客观的、直接的原因会被识解为主观的、间接原因,客观的、间接的原因会被构建为主观的、直接的原因。

一种面向IO Die的敏捷验证方法

IO Die可以用做IO扩展芯片,也可作为芯粒(chiplet)复用于多个项目。提出一种面向IO Die的敏捷验证方法,验证平台包括子系统级、簇级、全片级3个层次,可实现测试激励的跨层次复用;针对各验证层次的测试激励的自动生成方式进行优化,分别采用覆盖率驱动、可配置约束产生、多目标优化策略,提高测试激励的生成效率。实验结果表明,该方法在保证效率和可靠性的前提下,可以降低验证成本,缩短验证时间,快速获得已知合格裸片KGD。

Effects of magnesium and copper additions on tensile properties of Al-Si-Cr die casting alloy under as-cast and T5 conditions

Aluminum high pressure die casting(HPDC)technology has evolved in the past decades,enabling stronger and larger one-piece casting with significant part consolidation.It also offers a higher design freedom for more mass-efficient thin-walled body structures.For body structures that require excellent ductility and fracture toughness to be joined with steel sheet via self-piercing riveting(for instance,shock towers and hinge pillars,etc.),a costly T7 heat treatment comprising a solution heat treatment at elevated temperatures(450℃-500℃)followed by an over-ageing heat treatment is needed to optimize microstructure for meeting product requirement.To enable cost-efficient mass production of HPDC body structures,it is important to eliminate the expensive T7 heat treatment without sacrificing mechanical properties.Optimizing die cast alloy chemistry is a potential solution to improve fracture toughness and ductility of the HPDC components.The present study intends to tailor the Mg and Cu additions for a new Al-Si-Cr type die casting alloy(registered as A379 with The Aluminum Association,USA)to achieve the desired tensile properties without using T7 heat treatment.It was found that Cu addition should be avoided,as it is not effective in enhancing strength while degrades tensile ductility.Mg addition is very effective in improving strength and has minor impact on tensile ductility.The investigated Al-Si-Cr alloy with a nominal composition of Al-8.5wt.%Si-0.3wt.%Cr-0.2wt.%Fe shows comparable tensile properties with the T7 treated AlSi10MnMg alloy which is currently used for manufacturing shock towers and hinge pillars.

Henry入路蝶形钢板内固定治疗桡骨远端双柱Die-punch骨折

目的:探讨Henry入路蝶形钢板切开复位内固定治疗桡骨远端双柱Die-punch骨折的临床疗效。方法:选择2018年1月至2021年6月采用Henry手术入路切开复位内固定治疗的26例桡骨远端双柱Die-punch骨折患者,男14例,女12例;年龄20~75(44.2±3.4)岁。观察术后并发症情况,术后12个月采用Gartland-Werley评分标准进行腕关节功能评价。结果:26例患者均获得随访,时间10~18(13.4±0.8)个月。所有骨折均获得骨性愈合,时间8.5~15.8(11.4±0.5)周。所有患者手术切口都Ⅰ期愈合,无伤口感染、血管神经损伤及内固定失效等病例。术后12个月GarthndWerley评分(3.65±0.36)分,优16例,良8例,可2例。结论:通过掌侧Henry入路,使用蝶形钢板切开复位内固定治疗桡骨远端双柱Die-punch骨折,可获得满意的临床疗效。

汽车车灯支架压铸工艺CAE分析及模具设计

分析了汽车车灯支架的结构特点,进行了压铸工艺设计,并应用ProCAST软件对该铝合金压铸件的充型过程、压铸模具热平衡和温度场进行了数值模拟分析,预测缺陷产生的位置及原因,根据预测结果对模具结构进行了优化。实际生产表明,采用优化后的模具设计方案提升了铸件质量。

铸造增压压力对汽车用AlSi9Mg铝合金组织和力学性能的影响

通过改变低压铸造过程中不同增压压力来研究其对AlSi9Mg合金显微组织与力学性能的影响。结果表明,在高增压压力制备的AlSi9Mg合金样品具有更加致密的显微组织及更接近球形的共晶Si颗粒。同时,由于具有更好的填充能力,高增压压力下合金的气孔缺陷大大减少,合金具有更优异的力学性能。在90、150、210 kPa3种不同级别的增压压力下,晶粒尺寸呈逐渐减小的趋势,对应的合金晶粒尺寸和二次枝晶臂间距分别为246、197、149μm,44.9、37.3、31.1μm;3种增压压力对应的密度和孔隙率分别为2.656、2.659、2.674 g/cm^(3),0.96%、0.79%、0.38%;AlSi9Mg合金的抗拉强度、屈服强度和伸长率分别为238.76、174.68 MPa和3.14%;252.43、177.47 MPa和4.61%;256.10、178.81 MPa和6.85%,分别提高了7.26%、2.36%、118.15%。

“新理念荟萃”还是“伪科学集腋”?——德国音乐期刊《序列》(die Reihe)探赜

《序列》(dieReihe)是20世纪五六十年代具有国际影响力的德语音乐学术期刊。该刊汇集了20世纪中叶西方诸多杰出作曲家、音乐理论家与科学家的亲笔文稿,具有重要研究意义和价值。1957年《序列》英文版发行以降,引起了西方音乐界和科学界的广泛热议,其中包含许多针对《序列》“伪科学”性质的批评与指责。虽然《序列》存在行文晦涩、概念误用、英文错译与欠乏规范等问题,但该刊凝聚了鲜明的前沿意识以及丰富而深刻的理论洞见,其价值及意义无可非议。

钛合金薄壁构件快速加热冷模热冲压成形技术进展

为了解决钛合金薄壁构件热成形效率低、成本高、组织性能控制难度大等问题,近年来钛合金冷模热冲压成形技术受到关注。在该新技术中利用室温模具对加热后的钛合金板材进行快速冲压成形和模内快速冷却,由于取消了模具加热,可以变革性地提高钛合金薄壁构件成形效率、降低成本。然而,与传统等温成形不同,在冷模热冲压成形过程中,钛合金板材温度不断下降,这对钛合金成形极限、回弹及组织性能等的控制提出了全新的挑战。分析了钛合金薄壁构件冷模热冲压成形技术特点及存在的问题,归纳了快速加热对钛合金组织性能的影响规律,综述了钛合金薄壁构件快速加热冷模热冲压成形工艺进展,最后对该技术未来的发展方向进行了展望。

善生与善终:中国生命文化的安宁追求

中国传统生命文化立足于生死一体,有一整套对临终“安宁”的文化叙事。在根本理念上,强调“送死”是比“养生”更重要的人生大事,而能够“善终”则是人的幸福追求。在行为决策上,强调个人自主与家庭协商相结合的家庭自主模式;在策略路径上,主张遵守“礼制”,特别设计出一套临终礼仪,帮助人们走向“善终”;在目标价值上,强调“知生”以“知死”,活得好便可以死得好,由此可以实现生命价值的不朽;在精神信念上,则强调对“生死有命”的接纳,同时将“命限”转化为“使命”,从而升华对“天命”的体悟与认知,并在“生生不息”的信仰中接受死亡。

基于OBE理念的职教本科项目驱动式教学改革探究——以压铸模技术课程为例

依据行业发展方向,结合职业教育改革政策,从职教本科压铸模技术课程出发,以培养学生“知识+技能+创新”能力为目标,分析OBE教学理念在教学中的适用性,并从项目载体选择、项目实施、课程考核三个方面进行教学改革探索,使学生专业知识技能螺旋式提升,学习兴趣由被动变主动,创新思维得到有效锻炼,也为适应经济社会发展和技术技能的数字化设计与制造技术专业人才培养奠定基础。

水箱安装支架级进模设计

通过对安装支架的冲压工艺及单工序模成形进行分析,确定采用11道工序的级进模进行成形。为保证条料的同步移动和送料顺畅,下模采用浮动顶料机构,还介绍了条料的粗定位和精定位。模具经试冲,结果表明:设计的排样方案和模具结构合理可行,能满足安装支架的大批量生产需求。

4Cr5MoSiV1热作模具钢循环渗氮及热疲劳行为研究

针对4Cr5MoSiV1热作模具钢在使用过程中经受熔融铝液及冷却液的循环冲击,在热应力作用下容易产生热疲劳失效的问题。采用可控循环气体渗氮的方法分别在回火态和热疲劳态模具钢表面制备无铁氮化合物和有化合物的渗层,进行热疲劳性能测试。结果表明:循环渗氮制备的无化合物的渗层可以有效延缓热疲劳裂纹的萌生,抗热疲劳性能优于有化合物的渗层。同时,在裂纹产生前进行二次渗氮可以补充氮原子,重置压应力并增加硬度,进一步提升热疲劳抗性。

整体式副车架液态模锻及其性能

液态模锻是铝合金件高性能成型的先进工艺,文章将液态模锻技术用于整体式副车架成型,着重研究液锻工艺方案和液锻副车架性能的均匀性。模拟研究表明,单浇道液锻比设有辅助浇道的液锻汇流位置少、表面质量高、工艺出品率高。试生产发现,利用广州和德轻量化成型技术有限公司设计制造的HVSC2500T卧式液态模锻机进行A356.2铝合金副车架的单浇道液锻,能够获得完整无缺的副车架,本体取样拉伸强度可达320 MPa,延伸率达11.12%。但是,在远离浇道和存在汇流的位置普遍存在夹渣缺陷,副车架强度和塑性都较低。

火锅菜盆复合模设计

根据火锅菜盆的尺寸、结构和材料厚度,对其冲压工艺进行分析,并设计了“落料+第1次成形+拉深”复合模、第2次成形单工序模、侧冲孔单工序模。在复合模中,120°的斜边可视为拉深工序的压边圈,将第1次成形120°夹角的工序排在拉深工序前。在第2次成形70°夹角的单工序模的下模中设计了活动顶板,与上模的成形凸模将120°的斜边压住,防止120°的斜边变形。在“落料+第1次成形+拉深”复合模和第2次成形单工序模中,在下模成形零件的底部设置橡胶垫块,在上模向下运动时橡胶垫块的弹力将材料顶住,同时给上模向下运动腾出空间,防止模具零件卡死。

某电机齿轮冷挤压裂纹形成机理研究

针对材料为20Cr的某电机齿轮在冷挤压成形时内齿齿顶面上出现的裂纹缺陷,基于DEFORM-3D对其冷挤压过程进行了模拟,研究了其裂纹形成机理。有限元结果表明,内齿的金属流动速度小于中部及下部外齿的流动速度,内齿齿顶面上齿根处的金属流动速度最小,此处流动最不均匀,易产生应力集中;对齿面的最大主应力及损伤分布进行了分析,得出在内齿齿顶面上,中部及距离下端面1 mm左右的位置应力集中最明显,拉应力较大且大于材料抗拉强度,损伤值也较大且大于临界损伤值,会产生裂纹,与实际情况相符合。通过改变凹模入模角来控制成形缺陷情况,当凹模入模角为23°时,齿根处拉应力下降,损伤值减小,投入生产后次品率从原本的50%降为1%。