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在总结前人热裂纹研究的基础上，提出了热裂纹形成的凝固收缩补偿模型该模型将合金凝固过程按收缩补偿方式分为准液相区、可补缩区、不可补缩区、晶间搭桥区四个阶段．热裂纹形成于不可补缩区，晶间液相收缩产生孔洞，并在进一步收缩过程中扩展为热裂纹利用等径圆柱和等径圆球模型计算出理想状态下柱状晶和等轴晶不可补缩区液相体积分数范围分别为0．31％－93％和0．83％－26％对Al-Cu合金和Al-Si合金不可补缩温度间隔进行了计算，并与合金热裂倾向试验结果进行了比较，证明合金的不可补缩温度间隔越大，合金的热裂倾向越高在走向凝固热裂研究中发现了热裂纹中晶间搭桥的存在，以及裂纹断面上晶间搭桥破断留下的痕迹
On the basis of summarizing the previous research on hot cracking, the model of solidification and shrinkage compensation for the formation of hot cracks was proposed. This model divides the solidification process of the alloy into the quasi-liquid zone, shrinkable zone, irreplaceable zone, Four-stage bypass area. Hot cracks formed in the unreinforcible region, liquid crystal chamber between the shrinkage of the hole, and in the further shrinkage process to expand into a hot crack Equivalent diameter cylinder and the equivalent sphere model to calculate the ideal columnar crystals and equiaxed grains can not make up The shrinkage liquid phase volume fractions ranged from 0.31% -93% and 0.83% -26%, respectively. The incompressible temperature intervals of Al-Cu alloy and Al-Si alloy were calculated and compared with the hot tearing tendency test The results show that the larger the irreplaceable temperature interval of the alloy, the higher the hot cracking tendency of the alloy, the existence of intergranular bridging in the hot cracking and the intergranular bridging fracture in the crack cross section Under the traces